Ph. D., The University of Tokyo

Master of Engineering, The University of Tokyo

Bachelor of Engineering, The University of Electro-Communications

Optical Science and Engineering (Optical Metrology, Optical Information Processing, Holography, Statistical Optics)

Other, Other, Optical Science and Engineering

Apr. 2021 - Present
Utsunomiya University, Center for Optical Research and Education, Emeritus Fellow, Japan

Apr. 2012 - Present
The University of Electro-Communication, Emeritus Professor

Apr. 2012 - Mar. 2021
Utsunomiya University, Center for Optical Research and Education, Research Professor

Mar. 2013 - Aug. 2014
Stuttgart University, Institute for Applied Optics, Humboldt Guest Professor, Germany

Apr. 1990
The University of Electro-Communications, Professor

Mar. 1985 - Dec. 1985
Stanford University, Information Systems Laboratory, Visiting Scholar, 文部省派遣長期在外研究員, United States

May 1980
The University of Electro-Communications, Associate Professor

Apr. 1977
The University of Electro-Communications, Lecturer

Apr. 1975
Canon Inc., R&D Staff

Apr. 1974
The University of Tokyo, Institute of Industrial Science, JSPS Postdoctoral Fellow

Mar. 1974
The University of Tokyo, Graduate School of Engineering, Ph. D., Applied Physics

Mar. 1971
The University of Tokyo, Graduate School of Engineering, ME, Applied Physics

Mar. 1969
The University of Electro-Communications, Faculty of Electro Communications, BE

Mar. 2015 - Feb. 2017
理事長, 国際光技術検定協会, Society

Apr. 2010 - Mar. 2012
幹事長, 日本光学会, Society

Jan. 2007 - Dec. 2009
Board of Directors, SPIE (The International Society for Optical Engineering), Society

Jan. 2007 - Dec. 2009
理事, SPIE（国際光工学会）, Society

Jan. 2008 - Dec. 2008
Strategic Planning Committee, SPIE (The International Society for Optical Engineering), Society

Jan. 2008 - Dec. 2008
戦略計画委員会委員, SPIE（国際光工学会）, Society

Jan. 2008 - Dec. 2008
Nomination Committee, SPIE (The International Society for Optical Engineering), Society

Jan. 2008 - Dec. 2008
推薦委員会委員, SPIE（国際光工学会）, Society

Jan. 2007 - Dec. 2008
Engineering, Science and Technology Policy Committee, SPIE (The International Society for Optical Engineering), Society

Jan. 2007 - Dec. 2008
科学技術政策委員会委員, SPIE（国際光工学会）, Society

Jan. 2004 - Dec. 2005
Chair, Fellows Committee, SPIE (The International Society for Optical Engineering), Society

Jan. 2004 - Dec. 2005
フェロー審査委員長, SPIE（国際光工学会）, Society

2003 - 2005
業績賞委員会委員, 応用物理学会, Society

Jan. 2003 - Dec. 2003
Board of Directors, SPIE (The International Society for Optical Engineering), Society

Jan. 2003 - Dec. 2003
理事, SPIE（国際光工学会）, Society

Jan. 2003 - Dec. 2003
Stratigic Planning Committee, SPIE (The International Society for Optical Engineering), Society

Jan. 2003 - Dec. 2003
戦略計画委員会委員, SPIE（国際光工学会）, Society

Jan. 1994 - Dec. 2003
Associate Editor, Optical Review, The Optical Society of Japan, Society

May 2003
President's Asian Advisory Committee, SPIE (The International Society for Optical Engineering), Society

May 2003
アジア諮問委員会委員, SPIE（国際光工学会）, Society

2003
光・電子集積技術業績賞（林厳雄賞）選考委員会委員, 応用物理学会, Society

2001 - 2001
論文賞委員会委員, 応用物理学会, Society

Jan. 1995 - Dec. 1999
評議員, 応用物理学会, Society

1998 - 1999
副幹事長, 日本光学会, Society

1998 - 1998
推薦委員会委員, 応用物理学会, Society

Jan. 1993 - Dec. 1994
理事, 応用物理学会, Society

1983 - 1985
JJAP編集委員, 応用物理学会, Society

Mar. 2022
The Japan Society of Applied Physics
Contributions to the development of optical engineering through pioneering work in the fields of optical metrology, information optics, and imaging
Optical Engineering Award (Takano Eiichi Award), Mitsuo Takeda

Sep. 2020
The Optical Society
The inventions of Fourier fringe analysis and coherence holography
Emmett N. Leith Medal, Mitsuo Takeda
International academic award, United States

Jun. 2018
精密工学会（メカノフォトニクス専門委員会）
光計測分野における貢献
吉澤業績賞, 武田光夫

Aug. 2017
SPIE (International Society for Opics and Photonics) USA
The invention of the Fourier fringe analysis and its many industrial applications.
The SPIE Chandra S. Vikram Award, Mitsuo Takeda
International academic award, United States

Mar. 2013
Alexander von Humboldt Foundation, (Germany)
Achievements of research and education in the field of applied optics
Humboldt Research Award, Mitsuo Takeda
International academic award, Germany

Mar. 2012
The Japan Society of Applied Physics
The invention of Fourier fringe analysis and the developments of its application areas
Optics and Quantum Electronics Achievement Award (Hiroshi Takuma Award) Japan Society of Applied Physics, Mitsuo Takeda
Japan

Apr. 2011
Megurokai (Alumini Association of the University of Electro-Communications)
Achievements in optical research and education
Dishtinguished Alumni Award, Mitsuo Takeda
Others, Japan

Aug. 2010
SPIE (International Society for Opics and Photonics)
Eminent contributions to the development of holography and optical metrology
The SPIE Dennis Gabor Award, Mitsuo Takeda
International academic award, United States

Aug. 2007
The Japan Society of Applied Physics
Fellow of JSAP (Japan Society of Applied Physics), Mitsuo Takeda
Japan

Jun. 2007
Fellow of OSA (The Optical Society) USA, Mitsuo Takeda
United States

Sep. 1999
International Order of Knight of Holography
Poland
The Knight of Holography (Castle of Pultusk, Poland), Mitsuo Takeda
Poland

Jul. 1999
USA
Fellow of SPIE (The International Society for Optical Engineering), Mitsuo Takeda
United States

Preliminary experimental evaluation of microscopic imaging through thick biological tissues based on in-line phase-shift digital holography using near-infrared light
Manami Ohta; Shutaro Kodama; Kanami Ikeda; Yutaka Kano; Yoko Miyamoto; Wolfgang Osten; Mitsuo Takeda; Eriko Watanabe
Proceedings of SPIE - The International Society for Optical Engineering, 11521, 2020, We previously proposed a three-dimensional microscopic imaging system for objects hidden behind scattering media using in-line phase-shift digital holography, which simultaneously captures amplitude and phase information. However, as the thickness of the scattering medium increases, the influence of scattering is enhanced, and the reconstructed image of the object behind the scattering medium deteriorates. In this paper, we report the evaluation of this image using a near-infrared light source with a wavelength of 780 nm that is capable of deep tissue penetration. A favorable microscopic image of the object behind the rat-skin sample of 912 μm-thickness was successfully reconstructed.
International conference proceedings

Microscopic 3D imaging through scattering media based on in-line phase-shift digital holography
S. Kodama; K. Ikeda; Y. Miyamoto; W. Osten; M. Takeda; E. Watanabe
Digital Holography & 3-D Imaging (DH), W2B.4-1-W2B.4-2, May 2019, Peer-reviwed, We demonstrate microscopic three-dimensional imaging of an object hidden behind a diffuser by using in-line phase-shift digital holography. A spatial resolution of 2.9 μm was achieved, and highly accurate quantitative phase imaging and three-dimensional imaging were realized.
International conference proceedings, English

Recent progress on the unified theory of polarization and coherence for stochastic electromagnetic fields
Wei Wang; Juan Zhao; Xiaoying Hu; Steen G. Hanson; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, SPIE, 10612, 2018, Peer-reviwed, All optical fields undergo random fluctuation and the underlying theory referred to as coherence and polarization of optical fields has played a fundamental role as an important manifestation of the random fluctuations of the electric fields. In this paper, we reviewed our recent theoretical and experimental work on the unified theory of polarization and coherence including coherence tensor wave, degree of coherence tensor, degree of generalized Stokes parameters, and their applications including coherence tensor holography and two-point resolution of polarimetric imaging.
International conference proceedings, English

Scatter-plate microscope for lensless microscopy with diffraction limited resolution
Alok Kumar Singh; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
SCIENTIFIC REPORTS, NATURE PUBLISHING GROUP, 7, Sep. 2017, Peer-reviwed, Scattering media have always been looked upon as an obstacle in imaging. Various methods, ranging from holography to phase compensation as well as to correlation techniques, have been proposed to cope with this obstacle. We, on the other hand, have a different understanding about the role of the diffusing media. In this paper we propose and demonstrate a 'scatter-plate microscope' that utilizes the diffusing property of the random medium for imaging micro structures with diffraction-limited resolution. The ubiquitous property of the speckle patterns permits to exploit the scattering medium as an ultra-thin lensless microscope objective with a variable focal length and a large working distance. The method provides a light, flexible and cost effective imaging device as an alternative to conventional microscope objectives. In principle, the technique is also applicable to lensless imaging in UV and X-ray microscopy. Experiments were performed with visible light to demonstrate the microscopic imaging of USAF resolution test target and a biological sample with varying numerical aperture (NA) and magnifications.
Scientific journal, English

Exploiting scattering media for exploring 3D objects
Alok Kumar Singh; Dinesh N. Naik; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
LIGHT-SCIENCE & APPLICATIONS, CHINESE ACAD SCIENCES, CHANGCHUN INST OPTICS FINE MECHANICS AND PHYSICS, 6, Feb. 2017, Peer-reviwed, Scattering media, such as diffused glass and biological tissue, are usually treated as obstacles in imaging. To cope with the random phase introduced by a turbid medium, most existing imaging techniques recourse to either phase compensation by optical means or phase recovery using iterative algorithms, and their applications are often limited to two-dimensional imaging. In contrast, we utilize the scattering medium as an unconventional imaging lens and exploit its lens-like properties for lensless threedimensional (3D) imaging with diffraction-limited resolution. Our spatially incoherent lensless imaging technique is simple and capable of variable focusing with adjustable depths of focus that enables depth sensing of 3D objects that are concealed by the diffusing medium. Wide-field imaging with diffraction-limited resolution is verified experimentally by a single-shot recording of the 1951 USAF resolution test chart, and 3D imaging and depth sensing are demonstrated by shifting focus over axially separated objects.
Scientific journal, English

Experimental study on degree of coherence for stochastic electromagnetic fields
Juan Zhao; Mitsuo Takeda; Wei Wang
HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS VII, SPIE-INT SOC OPTICAL ENGINEERING, 10022, 100222D, 2017, All optical fields undergo random fluctuation and the degree of coherence defined as the normalized correlation function of optical fields has played a fundamental role as an important manifestation of the underlying random fluctuations. For randomly varying electromagnetic waves, the usual treatment of polarization based on the well-known Stokes parameters or polarization matrices is not adequate and a unified theory of coherence and polarization of random electromagnetic beams has been proposed by Wolf to elucidate the changes of polarization and coherence as the beam propagate.
In this paper, a novel optical geometry is proposed based on the polar-interference law of electromagnetic beams with its unique capability to visualize the mutual coherence tensor directly. Note the fact that wave equations govern the propagation of mutual coherence tensor, which can be regarded as a tensor wave. After retrieval of the complex functions for all the elements of coherence tensor from the recorded interferograms, we obtain the magnitude and the unit direction tensor for the coherence tensor wave and demonstrate the degree of coherence for stochastic electromagnetic fields with partial polarization and partial coherence experimentally for the first time.
International conference proceedings, English

3D polarization speckle as a demonstration of tensor version of the van Cittert-Zernike theorem for stochastic electromagnetic beams
Ning Ma; Juan Zhao; Steen G. Hanson; Mitsuo Takeda; Wei Wang
HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS VII, SPIE-INT SOC OPTICAL ENGINEERING, 10022, 100222F, 2017, Laser speckle has received extensive studies of its basic properties and associated applications. In the majority of research on speckle phenomena, the random optical field has been treated as a scalar optical field, and the main interest has been concentrated on their statistical properties and applications of its intensity distribution. Recently, statistical properties of random electric vector fields referred to as Polarization Speckle have come to attract new interest because of their importance in a variety of areas with practical applications such as biomedical optics and optical metrology. Statistical phenomena of random electric vector fields have close relevance to the theories of speckles, polarization and coherence theory.
In this paper, we investigate the correlation tensor for stochastic electromagnetic fields modulated by a depolarizer consisting of a rough-surfaced retardation plate. Under the assumption that the microstructure of the scattering surface on the depolarizer is as fine as to be unresolvable in our observation region, we have derived a relationship between the polarization matrix/coherency matrix for the modulated electric fields behind the rough-surfaced retardation plate and the coherence matrix under the free space geometry. This relation is regarded as entirely analogous to the van Cittert-Zernike theorem of classical coherence theory. Within the paraxial approximation as represented by the ABCD-matrix formalism, the three-dimensional structure of the generated polarization speckle is investigated based on the correlation tensor, indicating a typical carrot structure with a much longer axial dimension than the extent in its transverse dimension.
International conference proceedings, English

Holographic correloscopy for imaging a 3-D object hidden behind a diffuser: A review
M. Takeda; A. K. Singh; D. N. Naik; G. Pedrini; W. Osten
Technical Digest, International Symposium on Optical Memory 2016, ISOM’16 (Kyoto, Japan), 146-147, Oct. 2016, Invited
International conference proceedings, English

Holographic Correloscopy-Unconventional Holographic Techniques For Imaging a Three-Dimensional Object Through an Opaque Diffuser or Via a Scattering Wall: A Review
Mitsuo Takeda; Alok Kumar Singh; Dinesh Narayana Naik; Giancarlo Pedrini; Wolfgang Osten
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 12, 4, 1631-1640, Aug. 2016, Peer-reviwed, Invited, Techniques of unconventional holography, called holographic correloscopy, for imaging a three-dimensional (3-D) object through an opaque diffuser or via a scattering wall are reviewed. This paper is not intended to be a general overview. Instead, it will focus and shed light on less-known techniques termed coherence holography, photon-correlation holography, remote imaging digital holography, and dual-reference holography. This paper will introduce how they perform 3-D imaging through a diffuser or via a scattering wall with a thin but strongly scattering layer.
Scientific journal, English

Enhanced intensity variation for multiple-plane phase retrieval using a spatial light modulator as a convenient tunable diffuser
Percival F. Almoro; Quang Duc Pham; David Ignacio Serrano-Garcia; Satoshi Hasegawa; Yoshio Hayasaki; Mitsuo Takeda; Toyohiko Yatagai
OPTICS LETTERS, OPTICAL SOC AMER, 41, 10, 2161-2164, May 2016, Peer-reviwed, In the multiple-plane phase retrieval method, a tedious-to-fabricate phase diffuser plate is used to increase the axial intensity variation for a nonstagnating iterative reconstruction of a smooth object wavefront. Here we show that a spatial light modulator (SLM) can be used as an easily controllable diffuser for phase retrieval. The polarization modulation at the SLM facilitates independent formation of orthogonally polarized scattered and specularly reflected beams. Through an analyzer, the polarization states are filtered enabling beam interference, thereby efficiently encoding the phase information in the axially diverse speckle intensity measurements. The technique is described using wave propagation and Jones calculus, and demonstrated experimentally on technical and biological samples. (C) 2016 Optical Society of America
Scientific journal, English

Coherence holography and photon-correlation holography for imaging a 3-D object hidden behind a diffuser
M. Takeda
Symposium on super adaptive optics with wave field correction: Toward perfect imaging of the universe and live organisms, National Astronomical Observatory Japan, Mar. 2016, Invited
Symposium, English

Real-time 3D lensless imaging through scattering media
Alok Kumar Singh; Dinesh N. Naik; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
OPTICAL MEASUREMENT TECHNIQUES FOR STRUCTURES & SYSTEMS III, SHAKER PUBLISHING BV, 289-296, 2016, Peer-reviwed, Many techniques have been proposed recently to realize the goal of retrieving the information through diffusing medium or looking around the corner. Most of such techniques require a prior knowledge of the object or the complex transfer function of the diffusing medium. We developed a technique which do not require prior knowledge of the diffusing medium or object. Our method which is based on intensity correlation is lens-less and provides real-time imaging. By virtue of intensity cross-correlation this method also allow one to image 3D objects in real-time. Imaging of the objects kept between two diffuser is also possible. The experiments were demonstrated for different kind of objects with various diffusing mediums and the results verify our claim. The benefit of this techniques is that it works with spatially incoherent light sources as well.
International conference proceedings, English

Coherence and polarization of polarization speckle generated by a rough-surfaced retardation plate depolarizer
Ning Ma; Steen G. Hanson; Mitsuo Takeda; Wei Wang
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 32, 12, 2346-2352, Dec. 2015, Peer-reviwed, The coherence and polarization of polarization speckle, arising from a stochastic electromagnetic field with random change of polarization, modulated by a depolarizer are examined on the basis of the coherence matrix. The depolarizer is a rough-surfaced retardation plate with a random function of position introducing random phase differences between the two orthogonal components of the electric vector. Under the assumption of Gaussian statistics with zero mean, the surface model for the depolarizer of the rough-surfaced retardation plate is obtained. The propagation of the modulated fields through any quadratic optical system is examined within the framework of the complex ABCD matrix theory to show how the degree of coherence and polarization of the beam changes on propagation, including propagation in free space. (C) 2015 Optical Society of America
Scientific journal, English

Holographic correloscopy for imaging a 3-D object hidden behind a diffuser: A review
M. Takeda; A. K. Singh; D. N. Naik; G. Pedrini; W. Osten
International Workshop on Holography and Related Technologies 2015, IWH 2015 Digest (Okinawa, Japan), Tu1-1, 22-23, Dec. 2015, Invited
International conference proceedings, English

Statistics of the derivatives of complex signal derived from Riesz transform and its application to pseudo-Stokes vector correlation for speckle displacement measurement
Shun Zhang; Yi Yang; Steen G. Hanson; Mitsuo Takeda; Wei Wang
APPLIED OPTICS, OPTICAL SOC AMER, 54, 28, 8561-8565, Oct. 2015, Peer-reviwed, As an improvement of the well-known intensity correlation used in conventional electronic speckle photography, we have proposed a new technique, to the best of our knowledge, for displacement measurement referred to as pseudo-Stokes vector correlation (PSVC). To provide a theoretical background for the superiority of the proposed PSVC technique, we study the statistical properties of the spatial derivatives of the complex signal representation generated from the Riesz transform. Under the assumption of a Gaussian random process, a theoretical analysis for the pseudo Stokes vector correlation has been provided. Based on these results, we show mathematically that PSVC has a performance advantage over conventional intensity-based correlation technique. (C) 2015 Optical Society of America
Scientific journal, English

Fourier fringe analysis and its application to metrology of extreme physical phenomena: a review
M. Takeda
International Symposium on 3-D Imaging, Metrology, and Data Security, (Shenzen, China), Sep. 2015, Invited
International conference proceedings, English

Real-time imaging through thin scattering layer and looking around the opaque surface
A. K. Singh; D. N. Naik; G. Pedrini; M. Takeda; W. Osten
Digital Holography and Three-Dimensional Imaging (Shanghai, China), DTh3A.5, 24-28, May 2015
International conference proceedings, English

A comparison of diffracting and non-diffracting coherence functions based on full-field spatial coherence visualization system
Juan Zhao; Mitsuo Takeda; Wei Wang
INTERNATIONAL CONFERENCE ON PHOTONICS AND OPTICAL ENGINEERING (ICPOE 2014), SPIE-INT SOC OPTICAL ENGINEERING, 9449, 2015, Peer-reviwed, In this paper, we proposed a novel optical geometry for direct visualization of spatial coherence function. The full-field distribution of the coherence function from an incoherent circular aperture source is experimentally investigated. Meanwhile, the experiments of non-diffracting coherence function from an incoherent circular slit source have also been done. The experimental results show that the coherence function generated by an incoherent circular aperture source is in the form of Fresnel diffraction integral which diffracting during the propagation and the coherence function generated by an incoherent circular slit source is unaltered by propagating in free space.
International conference proceedings, English

Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix
Ning Ma; Steen G. Hanson; Tim K. Lee; Mitsuo Takeda; Wei Wang
SPECKLE 2015: VI INTERNATIONAL CONFERENCE ON SPECKLE METROLOGY, SPIE-INT SOC OPTICAL ENGINEERING, 9660, 2015, Peer-reviwed, Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory.
International conference proceedings, English

Fourier Fringe Demodulation
M. Takeda
P. Rastogi and E. Hack Eds., Phase Estimation in Optical Interferometry, CRC Press, Boca Raton, Chap.1, 1-30, 2015, Peer-reviwed, Invited
International conference proceedings, English

Riesz transforms in statistical signal processing and their applications to speckle metrology: a review
Wei Wang; Shun Zhang; Ning Ma; Steen G. Hanson; Mitsuo Takeda
INTERNATIONAL CONFERENCE ON PHOTONICS AND OPTICAL ENGINEERING (ICPOE 2014), SPIE-INT SOC OPTICAL ENGINEERING, 9449, 944904-1-944904-9, 2015, Invited, In this paper, a high-dimensional statistical signal processing is revisited with the aim of introducing the concept of vector signal representation derived from the Riesz transforms, which are the natural extension and generalization of the one-dimensional Hilbert transform. Under the new concepts of vector correlations proposed recently, the statistical properties of the vector signal representation for random signal are presented and some applications to speckle metrology developed recently are reviewed to demonstrate the unique capability of Riesz transforms.
International conference proceedings, English

Spatial Statistical Optics and Spatial Correlation Holography: A Review
Mitsuo Takeda; Wei Wang; Dinesh N. Naik; Rakesh K. Singh
OPTICAL REVIEW, OPTICAL SOC JAPAN, 21, 6, 849-861, Nov. 2014, Peer-reviwed, Invited, Classical statistical optics is revisited with the aim of introducing the concept of spatial statistical optics that places particular focus and special emphasis on spatial statistics of the optical field, rather than on their temporal statistics. The principles of emerging technology of statistical correlation holography based on spatial statistical optics are reviewed, and their unique capabilities for coherence and polarization shaping as well as synthesizing stochastic optical fields with desired statistical properties are introduced. (C) 2014 The Japan Society of Applied Physics
Scientific journal, English

Characterization of spatial polarization fluctuations in scattered field
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
JOURNAL OF OPTICS, IOP PUBLISHING LTD, 16, 10, 105010 (12pp), Oct. 2014, Peer-reviwed, We extend the concept of Poincare vector correlations for the characterization of spatial polarization fluctuations of scattered fields. Spatial (rather than temporal) dynamics of polarization in the scattered field is investigated experimentally by detecting instantaneous polarization with a specially designed polarization interferometer. Use of the Poincare-vector correlation in characterization is demonstrated by determining polarization dynamics of three different cases of scattered fields. This confirms usefulness of the proposed technique in diagnosis of scatterers. Under the condition of spatial ergodicity and Gaussian statistics of the scattered field, we replace the ensemble average of the instantaneous field with the space average, and estimate generalized Stokes parameters (GSPs) of the polarization speckles. Results of GSPs are used to obtain spatial correlation of the Poincare vectors.
Scientific journal, English

Measurement of extreme physical phenomena by Fourier fringe analysis: from sub-Ångstrom lattice distortion measurement to attosecond range pulse phase measurement
M. Takeda
International Conference on Photonics and Optical Engineering, icPOE 2014 (Xian, China), 21, Oct. 2014, Invited
International conference proceedings, English

Recent advances in digital holography [Invited]
Wolfgang Osten; Ahmad Faridian; Peng Gao; Klaus Koerner; Dinesh Naik; Giancarlo Pedrini; Alok Kumar Singh; Mitsuo Takeda; Marc Wilke
APPLIED OPTICS, OPTICAL SOC AMER, 53, 27, G44-G63, Sep. 2014, Peer-reviwed, Invited, This article presents an overview of recent advances in the field of digital holography, ranging from holographic techniques designed to increase the resolution of microscopic images, holographic imaging using incoherent illumination, phase retrieval with incoherent illumination, imaging of occluded objects, and the holographic recording of depth-extended objects using a frequency-comb laser, to the design of an infrastructure for remote laboratories for digital-holographic microscopy and metrology. The paper refers to current trends in digital holography and explains them using new results that were recently achieved at the Institute for Applied Optics of the University Stuttgart. (C) 2014 Optical Society of America
Scientific journal, English

Evaluation of Energy Flow Across an Optical Beam
Y. Miyamoto; A. Wada; T. Yonemura; M. Takeda
Optical Manipulation Conference (OMC '14), OMC8-5-1-OMC8-5-2, Apr. 2014, Peer-reviwed
International conference proceedings, English

Looking through a diffuser and around an opaque surface: A holographic approach
Alok Kumar Singh; Dinesh N. Naik; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
OPTICS EXPRESS, OPTICAL SOC AMER, 22, 7, 7694-7701, Apr. 2014, Peer-reviwed, Retrieving the information about the object hidden around a corner or obscured by a diffused surface has a vast range of applications. Over the time many techniques have been tried to make this goal realizable. Here, we are presenting yet another approach to retrieve a 3-D object from the scattered field using digital holography with statistical averaging. The methods are simple, easy to implement and allow fast image reconstruction because they do not require phase correction, complicated image processing, scanning of the object or any kind of wave shaping. The methods inherit the merit of digital holography that the micro deformation and displacement of the hidden object can also be detected. (C) 2014 Optical Society of America
Scientific journal, English

Spectrally resolved incoherent holography: 3D spatial and spectral imaging using a Mach-Zehnder radial-shearing interferometer
Dinesh N. Naik; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
OPTICS LETTERS, OPTICAL SOC AMER, 39, 7, 1857-1860, Apr. 2014, Peer-reviwed, Spatial and spectral information holds the key for characterizing incoherently illuminated or self-luminous objects, as well as for imaging fluorescence. We propose spectrally resolved incoherent holography using a multifunctional Mach-Zehnder interferometer that can introduce both a radial shear and a variable time delay between the interfering optical fields and permits the measurement of both spatial and temporal coherence functions, from which a 3D spatial and spectral image of the object is reconstructed. We propose and demonstrate the accurate 3D imaging of the object spectra by in situ calibration. (C) 2014 Optical Society of America
Scientific journal, English

Measurement of Energy Flow in an Optical Beam with Inverting Vortex
Y. Miyamoto; A. Wada; T. Yonemura; M. Takeda
9th International Conference on Optics-photonics Design and Fabrication (ODF '14) Technical Digest, 14S3-05-1-14S3-05-2, Feb. 2014, Peer-reviwed
International conference proceedings, English

Computational interferometry: A tutorial overview
M. Takeda
9th International Conference on Optics-photonics Design and Fabrication, ODF’14 (Itabashi, Japan), 93-94, Feb. 2014, Invited
International conference proceedings, English

Holographic spectral imaging of self-luminous objects using Mach-Zehnder radial shear interferometer with in situ calibration
D. N. Naik; G. Pedrini; W. Osten; M. Takeda
9th International Conference on Optics-photonics Design and Fabrication, ODF’14 (Itabashi, Japan), 423-424, Feb. 2014
International conference proceedings, English

Phase retrieval methods for optical imaging and metrology
G. Pedrini; A. Faridian; P. Gao; D. Naik; A. Singh; W. Osten; M. Takeda
2014 13TH WORKSHOP ON INFORMATION OPTICS (WIO), IEEE, 2014, Peer-reviwed, Phase retrieval methods have useful applications for optical imaging and metrology. We will see how holographic techniques may be used for increasing the resolution of microscopic images, measurement of residual stresses, imaging of occluded objects, imaging using incoherent illumination; furthermore, phase retrieval methods, which do not use a reference wave, are described.
International conference proceedings, English

Spatial stationarity of statistical optical fields for correlation holography
Mitsuo Takeda
Fringe 2013 - 7th International Workshop on Advanced Optical Imaging and Metrology, springer berlin, 143-148, 2014
International conference proceedings, English

Holographic imaging of a 3D object hidden behind a diffuser or around a corner
Alok Kumar Singh; Dinesh Narayana Naik; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
Fringe 2013 - 7th International Workshop on Advanced Optical Imaging and Metrology, springer berlin, 377-382, 2014
International conference proceedings, English

Ultra high-precision wavefront metrology using EUV low brightness source
Katsura Otaki; Naoki Kohara; Katsumi Sugisaki; Yoshinori Ichikawa; Yucong Zhu; Katsuhiko Murakami; Chidane Ouchi; Seima Kato; Masanobu Hasegawa; Tokuyuki Honda; Mitsuo Takeda
Fringe 2013 - 7th International Workshop on Advanced Optical Imaging and Metrology, springer berlin, 385-392, 2014, Invited
International conference proceedings, English

Transverse polarization structure of an optical vortex beam around the unfolding point in a birefringent crystal
Maruthi Manoj Brundavanam; Yoko Miyamoto; Mitsuo Takeda; Ken'ichi Nakagawa
Fringe 2013 - 7th International Workshop on Advanced Optical Imaging and Metrology, springer berlin, 611-615, 2014
International conference proceedings, English

Recording of 3D spatial and spectral information of self-luminous objects using a mach-zehnder radial shearing interferometer
Dinesh Narayana Naik; Giancarlo Pedrini; Mitsuo Takeda; Wolfgang Osten
Fringe 2013 - 7th International Workshop on Advanced Optical Imaging and Metrology, springer berlin, 715-718, 2014
International conference proceedings, English

Unconventional implementations and applications of digital holography
W. Osten; D. N. Naik; G. Pedrini; A. K. Singh; M. Takeda
Optics & Photonics Taiwan (OPTIC 2013), (Zhongli, Taiwan), Dec. 2013, Invited
International conference proceedings, English

Vectorial van Cittert-Zernike theorem based on spatial averaging: experimental demonstrations
R. K. Singh; D. N. Naik; H. Itou; M. M. Brundavanam; Y. Miyamoto; M. Takeda
Optics Letters, 38, 22, 4809-4812, Nov. 2013, Peer-reviwed
Scientific journal, English

Vectorial van Cittert-Zernike theorem based on spatial averaging: experimental demonstrations
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Maruthi M. Brundabanam; Yoko Miyamoto; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 38, 22, 4809-4812, Nov. 2013, Peer-reviwed, The van Cittert-Zernike theorem is extended to the vectorial regime based on spatial averaging over the observation plane, and experimental demonstrations are presented. The theorem connects complex vectorial source structure to the degree of coherence and polarization of the spatially fluctuating vectorial field in the far field. Experimentation is carried out by making use of the space averages as a replacement of ensemble averages for the Gaussian stochastic field. For quantitative comparison with the theorem, analytical and experimental results are presented for a rectangular aperture with different vectorial source structures. (C) 2013 Optical Society of America
Scientific journal, English

Spatial statistical optics for correlation holography
M. Takeda
Proc. 2013 Japan-Taiwan Bilateral Symposium in Nano/Bio-Photonics (Hamamatsu, Japan), 19-20, Nov. 2013, Invited

Spatial stationarity of statistical optical fields for coherence holography and photon correlation holography
Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 38, 17, 3452-3455, Sep. 2013, Peer-reviwed, The spatial stationarity of scattered optical fields constitutes a basic premise of coherence holography and photon correlation holography. Nevertheless, spatial stationarity seems to have attracted less attention and still remains a less familiar concept than temporal stationarity because it has been a common practice in statistical optics to assume temporal ergodicity and replace the ensemble average with the time average, rather than the space average. To form the theoretical basis for coherence holography and photon correlation holography, an investigation is made into the spatial stationarity of the statistical optical field, and combinations of a light source and an optical system are identified that can create spatially stationary scattered fields. The result justifies the principles of coherence holography and photon correlation holography, and the previously reported experiments. (C) 2013 Optical Society of America
Scientific journal, English

Synthetic statistical optics for coherence shaping," VIII Iberoamerican Conference on Optics
M. Takeda
XI Latin-american meeting on Optics, Lasers and Applications (Port, Portugal), Jul. 2013, Invited
International conference proceedings, English

Detailed measurement of the phase distribution of an optical beam with inverting vortex
Yoko Miyamoto; Atsushi Wada; Takashi Yonemura; Mitsuo Takeda
JOURNAL OF OPTICS, IOP PUBLISHING LTD, 15, 4, 044002 (7pp), Apr. 2013, Peer-reviwed, The detailed phase distribution of an astigmatic optical beam with inverting vortex is measured with a polarization based phase shifting interferometry. Energy flows and angular momentum density distribution within the beam cross sections are calculated from experimental data. Positive and negative angular momentum regions are observed both before and after vortex inversion, and regions of pure radial flow are identified.
Scientific journal, English

Characterization and compensation of phase distortions in holograms for generating and detecting doughnut beams
Yoko Miyamoto; Koichi Bito; Yusuke Ozaki; Atsushi Wada; Mitsuo Takeda
OPTICAL REVIEW, OPTICAL SOC JAPAN, 20, 2, 127-131, Mar. 2013, Peer-reviwed, Raster scan systems can introduce cubic and quadratic phase distortions in holograms for generating and detecting doughnut beams. The distortions can be corrected by subtracting corresponding terms from the hologram design. The compensation parameters can be determined by fabricating test holograms and applying rotational symmetry analysis to the intensity distribution of the generated beams. The 2- and 3-fold rotational symmetry components are shown to be effective in determining quadratic and cubic corrections respectively, and in the final corrected hologram the total contribution of anisotropic intensity components was reduced to 0.3%.
Scientific journal, English

Fourier fringe analysis and its application to metrology of extreme physical phenomena: a review
Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 52, 1, 20-29, Jan. 2013, Peer-reviwed, Invited, The paper reviews a technique for fringe analysis referred to as Fourier fringe analysis (FFA) or the Fourier transform method, with a particular focus on its application to metrology of extreme physical phenomena. Examples include the measurement of extremely small magnetic fields with subfluxon sensitivity by electron wave interferometry, subnanometer wavefront evaluation of projection optics for extreme UV lithography, the detection of sub-Angstrom distortion of a crystal lattice, and the measurement of ultrashort optical pulses in the femotsecond to attosecond range, which show how the advantages of FFA are exploited in these cutting edge applications. (c) 2012 Optical Society of America
Scientific journal, English

Recent progress in statistical information optics: Statistical information processing for optics
Wei Wang; Juan Zhao; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, SPIE, 9066, 906603, 2013, Invited, In this paper, we reviewed our recent work on the statistical information processing for optics including coherence diffraction, mutual coherence tensor, and the associated propagation properties, which we recently proposed and experimentally demonstrated. We will emphasize the importance of noting mathematical analogies in optics and physical phenomena, which give insights into the methodology for developing new techniques. © 2013 Copyright SPIE.
International conference proceedings, English

Relation between vectorial source structure and coherencepolarization of light
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Maruthi M. Brundavanam; Yoko Miyamoto; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, 8788, 87880O, 2013, A relation between vectorial source structure and coherence-polarization of the fluctuating field is established. This relation connects the source structure to the degree of coherence by Fourier relation, and this is extension of the van Cittert-Zernike theorem to the vectorial regime. Experimental verification of the proposed theorem is presented by making use of space averages as replacement of ensemble averages for Gaussian stochastic field. Both experimental and analytical results are obtained for different polarized sources, and good agreements between two justify use of space average as replacement of ensemble average in the spatially fluctuating field. © 2013 SPIE.
International conference proceedings, English

Polarization Structure of an Optical Vortex Beam near its Unfolding Point in a Birefringent Crystal
M. M. Brundavanam; Y. Miyamoto; M. Takeda; K. Nakagawa
International Workshop on Laser Science (IWLS), P-21, Oct. 2012
International conference proceedings, English

Coherence holography: Principle and applications
Mitsuo Takeda; Daniel Weiß; Dinesh N. Naik
Optical Imaging and Metrology: Advanced Technologies, Wiley-VCH, Chap. 11, 239-253, 23 Aug. 2012, Invited
In book, English

Coherence holography: Principle and applications
Mitsuo Takeda; Daniel Weiß; Dinesh N. Naik
Optical Imaging and Metrology: Advanced Technologies, Wiley-VCH, 239-253, 23 Aug. 2012, Invited
In book, English

Observation of spatial polarization structure near unfolding point of an optical vortex beam using a birefringent Mach-Zehnder interferometer
M. M. Brundavanam; Y. Miyamoto; R. K. Singh; D. N. Naik; M. Takeda; K. Nakagawa
The Nature of Light: Light in Nature IV, Proc. SPIE, 8480, 848008, Aug. 2012, Peer-reviwed
International conference proceedings, English

Coherence holography by achromatic 3-D field correlation of generic thermal light with an imaging Sagnac shearing interferometer
Dinesh N. Naik; Takahiro Ezawa; Rakesh Kumar Singh; Yoko Miyamoto; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 20, 18, 19658-19669, Aug. 2012, Peer-reviwed, We propose a new technique for achromatic 3-D field correlation that makes use of the characteristics of both axial and lateral magnifications of imaging through a common-path Sagnac shearing interferometer. With this technique, we experimentally demonstrate, for the first time to our knowledge, 3-D image reconstruction of coherence holography with generic thermal light. By virtue of the achromatic axial shearing implemented by the difference in axial magnifications in imaging, the technique enables coherence holography to reconstruct a 3-D object with an axial depth beyond the short coherence length of the thermal light. (C) 2012 Optical Society of America
Scientific journal, English

Single-shot full-field interferometric polarimeter with an integrated calibration scheme
Dinesh N. Naik; Rakesh Kumar Singh; Hitoshi Itou; Maruthi M. Brundavanam; Yoko Miyamoto; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 37, 15, 3282-3284, Aug. 2012, Peer-reviwed, A simple interferometric polarimeter with an integrated calibration scheme is proposed for accurate and fast mapping of the state of polarization (SOP). Conventional single-shot polarimeters that detect the amplitude and phase of orthogonally polarized field components by interferometry using Fourier fringe analysis suffers from errors caused by the imperfect reference beam and ambiguity in the spatial carrier frequency in the fringe pattern. In the proposed system, the integrated calibration scheme eliminates those error sources and enables accurate measurement of SOP without prior knowledge of the reference beam and the spatial carrier frequency. (C) 2012 Optical Society of America
Scientific journal, English

See-through imaging of 3-D object hidden behind a diffuser by unconventional correlation holography
M. Takeda
4th International Workshop on Perspectives of Optical Imaging and Metrology, HOLOMET 2012 (Utsunomiya, Japan), 36, Jul. 2012, Invited
International conference proceedings, English

Coherence Holography: Unconventional imaging with a synthetic coherence function
M. Takeda
8th International Conference on Optics-photonics Design & Fabrication, ODF’12 (St. Petersburg, Russia), 189-190, Jul. 2012, Invited
International conference proceedings, English

Characterization and compensation of phase distortions in holograms for generating and detecting doughnut beams
Y. Miyamoto; K. Bito; Y. Ozaki; A. Wada; M. Takeda
8th International Conference on Optics-photonics Design & Fabrication, ODF’12 (St. Petersburg, Russia), 27-28, Jul. 2012
International conference proceedings, English

Interferometric Astro-coronagraphy
A. Tavrov; T. Kurokawa; J. Nishikawa; M. Takeda
8th International Conferece on Optics-photonics Design & Fabrication, ODF’12 (St. Petersburg, Russia), 313-314, Jul. 2012
International conference proceedings, English

Interferometer setup for the observation of polarization structure near the unfolding point of an optical vortex beam in a birefringent crystal
Maruthi M. Brundavanam; Yoko Miyamoto; Rakesh Kumar Singh; Dinesh N. Naik; Mitsuo Takeda; Ken'ichi Nakagawa
OPTICS EXPRESS, OPTICAL SOC AMER, 20, 12, 13573-13581, Jun. 2012, Peer-reviwed, We propose a novel birefringent interferometer setup for the study of unfolding points, and obtain for the first time to our knowledge the spatial polarization structure very near the unfolding point of a uniformly polarized optical vortex beam propagating in a birefringent crystal. The unfolding point is reconstructed by folding back the two separated eigen-beams at the output of the birefringent crystal into a single beam using another identical birefringent crystal, resulting in a birefringent interferometer of Mach-Zehnder type. We also demonstrate that the separation near the unfolding point can be varied by a small rotation of the second crystal. (C) 2012 Optical Society of America
Scientific journal, English

Laser speckle reduction by multimode optical fiber bundle with combined temporal, spatial, and angular diversity
Dalip Singh Mehta; Dinesh N. Naik; Rakesh Kumar Singh; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 51, 12, 1894-1904, Apr. 2012, Peer-reviwed, We report significant speckle reduction in a laser illumination system using a vibrating multimode optical fiber bundle. The optical fiber bundle was illuminated by two independent lasers simultaneously. The beams from both lasers were first expanded and collimated and were further divided into multiple beams to illuminate the fiber optic bundle with normal and oblique incidence. Static diffusers were also placed at the input and output faces of the fiber bundle, thus introducing the spatial as well as angular diversity of illumination. Experiments were carried out both in free space and in imaging geometry configuration. Standard deviation, speckle contrast and signal-to-noise ratio of the images were computed, and the results were compared with those of white light illumination. Speckle contrast close to that of white light was obtained using a vibrating fiber bundle with combined temporal, spatial, and angular diversities of the illumination. (C) 2012 Optical Society of America
Scientific journal, English

Fourier fringe analysis applied for unconventional scientific and industrial metrologies of extreme physical phenomena: A review
M. Takeda
5th International Conference on Optical Measurement Techniques for Structures and Systems, OPTIMESS 2012, (Antwerp, Belgium), Apr. 2012, Invited
International conference proceedings, English

Stokes holography
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 37, 5, 966-968, Mar. 2012, Peer-reviwed, A new technique, referred to as Stokes holography, is proposed and experimentally demonstrated for controlled synthesis of generalized Stokes parameters in 3D space using Stokes fringes. Stokes fringes are polarization fringes which permit to record and reconstruct complete wavefront. Full use of Stokes fringes in a single step is realized by scattering complex field and subsequently reconstructing using spatial averaging of the randomly scattered field. Mathematical formulations are derived and supported by experimental results of 3D object reconstruction in generalized Stokes parameters. (C) 2012 Optical Society of America
Scientific journal, English

A coronagraph system with unbalanced nulling interferometer: progresses of dynamic range
Jun Nishikawa; Kaito Yokochi; Naoshi Murakami; Lyu Abe; Takayuki Kotani; Motohide Tamura; Takashi Kurokawa; Alexander Tavrov; Mitsuo Takeda; Hiroshi Murakami
SPACE TELESCOPES AND INSTRUMENTATION 2012: OPTICAL, INFRARED, AND MILLIMETER WAVE, SPIE-INT SOC OPTICAL ENGINEERING, 8442, 2012, Peer-reviwed, We have studied a coronagraph system with an unbalanced nulling interferometer (UNI). It consists of the UNI, adaptive optics, and a coronagraph. An important characteristic is a magnification of the wavefront aberrations in the UNI stage, which enables us to compensate for the wavefront aberrations beyond the AO systems capabilities. In our experiments, we have observed the stable aberration magnification of about 6 times and compensation to about lambda/100 rms corresponding to lambda/600 rms virtually. As a result, at the final focal plane of a 3-dimensional Sagnac interferometric nulling coronagraph, we have obtained the extra speckle reduction of better than 0.07 by the advantage of the UNI-PAC system. In order to obtain better contrast, we consider improvement of the optics with an 8OPM coronagraph, a dual feedback control, an unbalanced nulling interferometer with 4QPM or VVM, and a wavefront correction inside the UNI.
International conference proceedings, English

Characterization of polarization speckle
R. K. Singh; D. N. Naik; H. Itou; Y. Miyamoto; M. Takeda
Second International Conference on Trends in Optics and Photonics (ICONTOP 11), 43-48, Dec. 2011, Peer-reviwed
International conference proceedings, English

Photon correlation holography
D. N. Naik; R. K. Singh; T. Ezawa; Y. Miyamoto; M. Takeda
2011 Taiwan-Japan Bilateral Symposium in Nano/Bio-photonics (Tainan, Taiwan), 7-8, Nov. 2011, Invited
International conference proceedings, English

Intensity-correlation holography: a review
D. N. Naik; R. K. Singh; T. Ezawa; Y. Miyamoto; M. Takeda
OIE’11, The Nineth Japan-Finland Joint Symposium on Optics in Engineering, 62-63, Sep. 2011, Peer-reviwed
International conference proceedings, English

Detection of superposition in the orbital angular momentum of photons without excess components and its application in the verification of non-classical correlation
Y. Miyamoto; D. Kawase; M. Takeda; K. Sasaki; S. Takeuchi
Journal of Optics, 13, 6, 064027, Jun. 2011, Peer-reviwed
Scientific journal, English

Vectorial coherence holography
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 19, 12, 11558-11567, Jun. 2011, Peer-reviwed, Extension of coherence holography to vectorial regime is investigated. A technique for controlling and synthesizing optical fields with desired elements of coherence-polarization matrix is proposed and experimentally demonstrated. The technique uses two separate coherence holograms, each of which is assigned to one of the orthogonal polarization components of the vectorial fields. (C) 2011 Optical Society of America
Scientific journal, English

Common-path achromatic rotational-shearing coronagraph
Alexander Tavrov; Oleg Korablev; Leonid Ksanfomaliti; Alexander Rodin; Pavel Frolov; Jun Nishikwa; Motohide Tamura; Takashi Kurokawa; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 36, 11, 1972-1974, Jun. 2011, Peer-reviwed, To suppress starlight for direct exoplanet observation, we propose a common-path achromatic rotational-shearing coronagraph (CP-ARC), which is an interferocoronagraph with an angular-adjustable field rotator. The CP-ARC aims to maintain unwanted detection of stellar light, which can be suppressed incompletely by interference because of the finite diameter of the star. Compared to the previous interferocoronagraph, which had a nonadjustable 180 field rotation, the proposed CP-ARC can improve the coronagraphic contrast by several orders if the CP-ARC is combined with medium or large telescopes where the companion-star separation is optically resolved by more than a few Airy radii. The CP-ARC is made robust against mechanical disturbances due to the common-path interferometer principle. (C) 2011 Optical Society of America
Scientific journal, English

Coherence Holography: A Tutorial Review
M. Takeda
OSA Topical Meeting on Digital Holography and Three-Dimensional Imaging (DH), (Tokyo, Japan), DTuE2, May 2011, Invited
International conference proceedings, English

Holographic reconstruction using intensity interferometry
D. N. Naik; R. K. Singh; T. Ezawa; Y. Miyamoto; M. Takeda
OSA Topical Meeting on Digital Holography and Three-Dimensional Imaging (DH), DWD, May 2011
International conference proceedings, English

Realtime 3D profilometer using GPU and multicore CPU
Y. Miyamoto; A. Wada; T. Iizuka; T. Suzuki; T. Nakayama; K. Yanagawa; S. Aoki; T. Toriu; M. Kawana; T. Nishino; M. Takeda
OSA Topical Meeting on Digital Holography and Three-Dimensional Imaging (DH), DTuC, May 2011
International conference proceedings, English

Holographic control of coherence and polarization of light
R. K. Singh; D. Naik; H. Itou; Y. Miyamoto; M. Takeda
OSA Topical Meeting on Digital Holography and Three-Dimensional Imaging (DH), DTuB2, May 2011
International conference proceedings, English

Speckle level suppression using an unbalanced nulling interferometer in a high-contrast imaging system
Kaito Yokochi; Naoshi Murakami; Jun Nishikawa; Lyu Abe; Motohide Tamura; Alexander V. Tavrov; Mistuo Takeda; Takashi Kurokawa
OPTICS EXPRESS, OPTICAL SOC AMER, 19, 6, 4957-4969, Mar. 2011, Peer-reviwed, High-contrast imaging systems with a stellar halo suppression level of 10(-10) are required for direct detection of Earth-like extra-solar planets. We investigated a novel high-contrast imaging system with an unbalanced nulling interferometer (UNI) followed by phase and amplitude correction (PAC), which not only can reduce starlight but also can suppress the speckle level caused by wavefront aberrations. We successfully demonstrated that wavefront aberrations were sufficiently magnified by the UNI and the magnified aberrations were effectively corrected in amplitude and phase with two deformable mirrors. We confirmed that the suppression level of the speckle pattern with the proposed optics was beyond the limit of the adaptive optics performance. (C) 2011 Optical Society of America
Scientific journal, English

Speckle level suppression using an unbalanced nulling interferometer in a high-contrast imaging system
Kaito Yokochi; Naoshi Murakami; Jun Nishikawa; Lyu Abe; Motohide Tamura; Alexander V. Tavrov; Mistuo Takeda; Takashi Kurokawa
OPTICS EXPRESS, OPTICAL SOC AMER, 19, 6, 4957-4969, Mar. 2011, Peer-reviwed, High-contrast imaging systems with a stellar halo suppression level of 10(-10) are required for direct detection of Earth-like extra-solar planets. We investigated a novel high-contrast imaging system with an unbalanced nulling interferometer (UNI) followed by phase and amplitude correction (PAC), which not only can reduce starlight but also can suppress the speckle level caused by wavefront aberrations. We successfully demonstrated that wavefront aberrations were sufficiently magnified by the UNI and the magnified aberrations were effectively corrected in amplitude and phase with two deformable mirrors. We confirmed that the suppression level of the speckle pattern with the proposed optics was beyond the limit of the adaptive optics performance. (C) 2011 Optical Society of America
Scientific journal, English

Optical Vortex Metrology
Wei Wang; Steen G. Hanson; Mitsuo Takeda
Advances in Speckle Metrology and Related Techniques, Wiley-VCH, Chap.5, 207-238, 21 Feb. 2011, Invited
In book, English

Measurements of extreme physical phenomena by Fourier fringe analysis: a review
Mitsuo Takeda
22ND CONGRESS OF THE INTERNATIONAL COMMISSION FOR OPTICS: LIGHT FOR THE DEVELOPMENT OF THE WORLD, SPIE-INT SOC OPTICAL ENGINEERING, 8011, paper 2284573, 2011, Invited, In this talk we review and introduce some of the examples of successful applications of the Fourier transform method (FTM) of fringe pattern analysis to the measurements of extreme physical phenomena, such as those involving ultra fast optical pulses, extremely small atomic displacements, and unconventional electron wave or EUV light, and show how the advantages of FTM are exploited in these cutting edge application areas.
International conference proceedings, English

Coherence Holography: Principle and Applications
M. Takeda; W. Wang; D. N. Naik; Y. Miyamoto
Proc. XXXV Symposium of Optical Society of India, International Conference on Contemporary Trends in Optics and Opto Electronics (Thiruvananthapuram, India), 8-9, Jan. 2011, Invited
International conference proceedings, English

Highly Stable Interferometric technique for polarization mapping
Dinesh N. Naik; Rakesh Kumar Singh; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
PHOTONICS 2010: TENTH INTERNATIONAL CONFERENCE ON FIBER OPTICS AND PHOTONICS, SPIE-INT SOC OPTICAL ENGINEERING, 8173, 817319-1-8, 2011, In this paper, we present an interferometric technique for full field polarization mapping using Fourier fringe analysis. Uniqueness of the technique lies in its high stability against surrounding vibration and capability of single shot measurement. Accuracy of the technique is verified by mapping of beam with known state of polarization and subsequently the technique is used to map polarization for various kinds of sample fields.
International conference proceedings, English

Photon correlation holography
Dinesh N. Naik; Rakesh Kumar Singh; Takahiro Ezawa; Yoko Miyamoto; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 19, 2, 1408-1421, Jan. 2011, Peer-reviwed, Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light. (c) 2011 Optical Society of America
Scientific journal, English

Absolute surface profilometry of an object with large gaps by means of monochromatic laser interferometry
Zhiqiang Liu; Kiyoshi Uchikawa; Mitsuo Takeda
OPTICAL MEASUREMENT SYSTEMS FOR INDUSTRIAL INSPECTION VII, SPIE-INT SOC OPTICAL ENGINEERING, 8082, 80820R-1-6, 2011, We propose a technique for monochromatic laser interferometry capable of absolute surface profilometry of an object with large height gaps exceeding a half wavelength. The technique does not use a broadband source, such as a low-coherence or multi-wavelength source, or a wavelength-tunable device, which causes a dispersion problem. Instead, we make use of the phase change of monochromatic light through the angular shift of illumination introduced by tilting the optical axis of the interferometer. For oblique illumination at angle theta, the phase difference between the test and reference surfaces separated by distance d is given by Delta phi = 2kd cos theta, where k = 2 pi/lambda is a wavenumber. In effect, the change of illumination angle theta functions as the change of wavelength lambda. Therefore, while using a monochromatic laser light source, we can realize the same effect as a multi-wavelength source. From the relation between the illumination angle and the phase change, the absolute distance d between the test and reference surfaces can be determined without ambiguity of an integer multiple of a half wavelength associated with monochromatic interferometry. The large gap height can be determined also without ambiguity from the change of the absolute distance d across the boundary of the gap. Because the resolution of the absolute distance measurement by means of illumination angle change is not high enough by itself, we enhance the resolution by the following procedure. We first estimate the gap height to an integer multiple of a half wavelength by tilting the optical axis. Then the fractional portion of the phase is measured by setting the optical axis perpendicular to the test surface as in conventional interferometry. By combining the integer and the fractional portion, we can determine the absolute gap height with high accuracy and a large dynamic range exceeding a half wavelength. We present an experimental demonstration with a traditional Twyman-Green interferometer, in which a He-Ne laser was used as a monochromatic light source, and a test surface with a similar to 0.1 mm height gap was formed by two block gauges attached to a flat surface. The repeatability for five measurements was found to be as high as 0.1nm (in 1 sigma).
International conference proceedings, English

Stokes holography for recording and reconstructing objects using polarization fringes
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
OPTICAL MEASUREMENT SYSTEMS FOR INDUSTRIAL INSPECTION VII, SPIE-INT SOC OPTICAL ENGINEERING, 8082, 808208-1-10, 2011, Peer-reviwed, In this paper, we propose and demonstrate Stokes holography for recording and reconstructing a object using polarization fringes. Reconstruction is carried out by scattering the polarization fringes through ground glass, and replacing the ensemble averages by space averages of the randomly scattered Gaussian field. Object encoded into polarization fringes are reconstructed into their corresponding elements of generalized Stokes parameters. Experimental and numerical results of a point object reconstruction are presented.
International conference proceedings, English

State of polarization mapping using a calibrated interferometric polarimeter
Dinesh N. Naik; Rakesh Kumar Singh; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
OPTICAL MEASUREMENT SYSTEMS FOR INDUSTRIAL INSPECTION VII, SPIE-INT SOC OPTICAL ENGINEERING, 8082, 80821T-1-7, 2011, We propose a simple scheme for accurate state of polarization (SOP) mapping with an interferometric polarimeter using Fourier transform method of fringe analysis. In single shot polarimeters that use Fourier transform method of fringe analysis, a spatial carrier frequency is introduced in the fringes of recorded interferogram either by introducing the relative tilt between the sample beam under test and a reference beam, as demonstrated by Ohtsuka and Oka or by passing the sample beam through birefringent optical components such as Wollaston prisms as demonstrated by Oka and Kaneko. In this technique, the amount of spatial carrier frequency that enabled to filter different terms in the Fourier spectrum of the recorded interferogram had to be calibrated with the use of light with a known SOP. Even in this case, the spatial carrier frequency introduced in the recorded interferogram is influenced by the relative tilt of the beam used for calibration. To eliminate the linear phase introduced by spatial carrier frequency, usually the spectrum around the carrier frequency location in the Fourier transform is shifted and brought to the centre. During this process an error of a fraction of a pixel in the shifting of the spectrum after filtering to remove the linear phase introduced by spatial carrier frequency will drastically change the measured SOP of light. For accurate SOP mapping, it is important that we eliminate the artifacts and errors due to the spatial carrier frequency in the single shot polarimeter that are otherwise very promising. In the present work, we propose a Mach-Zehnder interferometric polarimeter that uses a common path Sagnac interferometer to generate reference beams with orthogonal state of polarization. By taking advantage of the inherent stability of the proposed common path Sagnac interferometer against surrounding vibrations and air turbulences, a simple calibration scheme using a light of known state of polarization is used to map the state of polarization with better accuracy.
International conference proceedings, English

Verification of non-classical correlation in orbital angular momentum of photons without excess components
Yoko Miyamoto; Daisuke Kawase; Mitsuo Takeda; Keiji Sasaki; Shigeki Takeuchi
2011 Int. Quantum Electron. Conf., IQEC 2011 and Conf. Lasers and Electro-Optics, CLEO Pacific Rim 2011 Incorporating the Australasian Conf. Optics, Lasers and Spectroscopy and the Australian Conf., 2067-2068, 2011, We propose a method to detect photons in superposition of orbital angular momentum (OAM) states using a hologram and path interferometer, and its application to verification of non-classical correlation in photon pairs. The method is free from excess OAM components, and a simple assumption of classical OAM correlation between the two photons removes contributions from excess components from the coincidence curve as well, even when the proposed method is used only on one of the photons. © 2011 IEEE.
International conference proceedings, English

Coherence holography and photon-correlation holography: Marriage between holography and statistical optics
Mitsuo Takeda; Wei Wang; Dinesh N. Naik
TRIBUTE TO JOSEPH W. GOODMAN, SPIE-INT SOC OPTICAL ENGINEERING, 8122, 822207-1-5, 2011, Invited, We review two techniques of unconventional holography, coherence holography and photon-correlation holography, which we recently proposed and experimentally demonstrated. We will emphasize the importance of noticing mathematical analogies in optics and physical phenomena, which give insights into the methodology for developing new techniques.
International conference proceedings, English

Detection of higher-dimensional effects in orbital-angular-momentum entangled photon pairs
Y. Miyamoto; S. Aoki; D. Kawase; Y. Ozaki; S. Takeuchi; S. Zwick; M. Takeda; K. Sasaki
3rd International Conference on Updating Quantum Cryptography and Communications, 71, Oct. 2010
International conference proceedings, English

Statistics of spatial derivatives of Stokes parameters for isotropic random polarization field
Shun Zhang; Mitsuo Takeda; Wei Wang
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 27, 9, 1999-2003, Sep. 2010, Peer-reviwed, The statistical properties of the spatial derivatives of the Stokes parameters for a random polarization field are studied. Based on the Gaussian assumption for the electric fields, the six-dimensional joint probability density function for the derivatives of the Stokes parameters is obtained from the statistics of the derivatives of the random polarization field. Subsequently, three two-dimensional probability density functions of derivatives of each Stokes parameter and the corresponding six marginal probability density functions are given. Finally, the joint and marginal density functions of the magnitude of the gradient of Stokes parameters are also derived for the first time, to our knowledge. (C) 2010 Optical Society of America
Scientific journal, English

Improved illumination system for spatial coherence control
Zhiqiang Liu; Takashi Gemma; Joseph Rosen; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 49, 16, D12-D16, Jun. 2010, Peer-reviwed, An improved illumination system is proposed for creating a temporally coherent and spatially incoherent extended source to be used for spatial coherence control and reconstruction of a coherent hologram. Taking into account the fact that a rotating ground glass does not behave as an ideal Lambertian diffuser, the new illumination system tailors the directivity of the scattered lights to direct the lights efficiently into an interferometer so that a spatial coherence function can be better controlled and detected with higher fidelity. Experimental results are presented that demonstrate improved performance of the proposed system. (C) 2010 Optical Society of America
Scientific journal, English

Polarization interferometric nulling coronagraph for high-contrast imaging
Naoshi Murakami; Kaito Yokochi; Jun Nishikawa; Motohide Tamura; Takashi Kurokawa; Mitsuo Takeda; Naoshi Baba
APPLIED OPTICS, OPTICAL SOC AMER, 49, 16, D106-D114, Jun. 2010, Peer-reviwed, We propose a novel, high-contrast imager called a polarization interferometric nulling coronagraph (PINC) for direct detection of extrasolar planets. The PINC uses achromatic half-wave plates (HWPs) installed in a fully symmetric beam combiner based on polarizing beam splitters. Jones calculus suggests that a stellar halo suppression level of 10(-10) can be achieved at 5 lambda/D for a broad wavelength range from 1.6 to 2.2 mu m by using Fresnel-rhomb HWPs made of BK7. Laboratory experiments on the PINC used two laser light sources (wavelengths of lambda = 532 and 671 nm), and we obtained a halo suppression level of approximately 10(-6) at 5 lambda/D for both wavelengths. (C) 2010 Optical Society of America
Scientific journal, English

Real-time coherence holography
Dinesh N. Naik; Takahiro Ezawa; Yoko Miyamoto; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 18, 13, 13782-13787, Jun. 2010, Peer-reviwed, Coherence holography capable of real-time recording and reconstruction is proposed and experimentally demonstrated with a generic Leith-type coherence hologram. The coherence hologram is optically generated in real-time using a Mach-Zehnder interferometer and reconstructed using a Sagnac radial shearing interferometer. With this method one can create an optical field distribution with a desired spatial coherence function, and visualize the coherence function in real-time as the contrast and phase variations in an interference fringe pattern. The reconstructed image of the complex coherence function has been quantified with the Fourier transform method of fringe-pattern analysis. (C) 2010 Optical Society of America
Scientific journal, English

Unneeded azimuthal components in detection of photon orbital angular momentum superposition states
Y. Miyamoto; S. Aoki; D. Kawase; Y. Ozaki; S. Takeuchi; S. Zwick; M. Takeda; K. Sasaki
17th Central-European Workshop on Quantum Optics, 1, Jun. 2010, Peer-reviwed
International conference proceedings, English

400 Years of Optical Instrumentation: feature introduction
Daniel Malacara; Joanna Schmit; Malgorzata Kujawinska; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 49, 16, YO11-YO11, Jun. 2010, Peer-reviwed
Scientific journal, English

Phase-shift coherence holography
Dinesh N. Naik; Takahiro Ezawa; Yoko Miyamoto; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 35, 10, 1728-1730, May 2010, Peer-reviwed, We propose and experimentally demonstrate a new reconstruction scheme for coherence holography using computer-generated phase-shift coherence holograms. A 3D object encoded into the spatial coherence function is reconstructed directly from a set of incoherently illuminated computer-generated holograms with numerically introduced phase shifts. Although a rotating ground glass is used to introduce spatially incoherent illumination, the phase-shifting portion of the system is simple and free from mechanically moving components. (C) 2010 Optical Society of America
Scientific journal, English

Pseudo-Stokes Vector Correlation From Complex Signal Representation of a Speckle Pattern and Its Applications to Micro-Displacement Measurement
W. Wang; R. Ishijima; A. Matsuda; S. G. Hanson; M. Takeda
STRAIN, WILEY-BLACKWELL PUBLISHING, INC, 46, 1, 12-18, Feb. 2010, Peer-reviwed, As an improvement of the intensity correlation used widely in conventional electronic speckle photography, we propose a new technique for displacement measurement based on correlating Stokes-like parameters derivatives for transformed speckle patterns. The method is based on a Riesz transform of the intensity speckle pattern, which converts the original real-valued signal into a complex signal. In closest analogy to the polarisation of a vector wave, the Stokes-like vector constructed from the spatial derivative of the generated complex signal has been applied for correlation. Experimental results are presented that demonstrate the validity and advantage of the proposed pseudo-Stokes vector correlation technique over conventional intensity correlation technique.
Scientific journal, English

A Coronagraph with an Unbalanced Nulling Interferometer and Adaptive Optics
J. Nishikawa; K. Yokochi; N. Murakami; L. Abe; T. Kotani; M. Tamura; T. Kurokawa; A. V. Tavrov; M. Takeda
PATHWAYS TOWARDS HABITABLE PLANETS, ASTRONOMICAL SOC PACIFIC, 430, 513-+, 2010, Peer-reviwed, A coronagraph system with an unbalanced nulling interferometer (UNI) is described. It consists of an adaptive optics (AO), the UNI, a second AO, and a coronagraph. Wavefront corrections and star light rejections are made twice. The UNI provides a magnification of wavefront aberrations and makes it possible to compensate for the wavefront aberrations beyond the AO system capabilities. Experimental results proved the principle of the UNI by wavefront measurements in the pupil plane.
International conference proceedings, English

Polarization speckles and generalized Stokes vector wave: a review
Mitsuo Takeda; Wei Wang; Steen G. Hanson
SPECKLE 2010: OPTICAL METROLOGY, SPIE-INT SOC OPTICAL ENGINEERING, 7387, 2010, Peer-reviwed, We review some of the statistical properties of polarization-related speckle phenomena, with an introduction of a less known concept of polarization speckles and their spatial degree of polarization. As a useful means to characterize two-point vector field correlations, we review the generalized Stokes parameters proposed by Korotkova and Wolf, and introduce its time-domain representation to describe the space-time evolution of the correlation between random electric vector fields at two different space-time points. This time-domain generalized Stokes vector, with components similar to those of the beam coherence polarization matrix proposed by Gori, is shown to obey the wave equation in exact analogy to a coherence function of scalar fields. Because of this wave nature, the time-domain generalized Stokes vector is referred to as generalized Stokes vector wave in this paper.
International conference proceedings, English

Conservation laws in quantum-correlation-function dynamics
Wei Wang; Mitsuo Takeda
Advances in Optical Technologies, 2010, Article ID 171254, 1-8, 2010, Peer-reviwed, For a complete and lucid discussion of quantum correlation, we introduced two new first-order correlation tensors defined as linear combinations of the general coherence tensors of the quantized fields and derived the associated coherence potentials governing the propagation of quantum correlation. On the basis of these quantum optical coherence tensors, we further introduced new concepts of scalar, vector and tensor densities and presented some related properties, such as conservation laws and the wave-particle duality for quantum correlation, which provide new insights into photon statistics and quantum correlation. Copyright © 2010 W.Wang and M. Takeda.
Scientific journal, English

A coronagraph system with unbalanced nulling interferometer: progresses of wavefront correction
Jun Nishikawa; Kaito Yokochi; Naoshi Murakami; Lyu Abe; Takayuki Kotani; Motohide Tamura; Takashi Kurokawa; Alexander V. Tavrov; Mitsuo Takeda; Hiroshi Murakami
SPACE TELESCOPES AND INSTRUMENTATION 2010: OPTICAL, INFRARED, AND MILLIMETER WAVE, SPIE-INT SOC OPTICAL ENGINEERING, 7731, 77314O1-6, 2010, Peer-reviwed, We have proposed a four-stage coronagraph system with an unbalanced nulling interferometer (UNI). It consists of a first adaptive optics (AO), the UNI, a second AO, and a coronagraph. An important feature is a magnification of the wavefront aberrations in the UNI stage, which enables us to compensate for the wavefront aberrations beyond the AO systems capabilities. In our experiments, we have observed the aberration magnification of about 6 times and compensated to about lambda/100 rms corresponding to lambda/600 rms virtually, and its performance is becoming stable. We have put a 3-dimensional Sagnac interferometric nulling coronagraph at the final stage of the system and tried to see the speckle reduction with the UNI-PAC system.
International conference proceedings, English

3-D coherence holography using a commercial projector for display and incoherent illumination of a coherence hologram
Dinesh N. Naik; Takahiro Ezawa; Rakesh Kumar Singh; Yoko Miyamoto; Mitsuo Takeda
INTERFEROMETRY XV: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 7790, 77900Q1-8, 2010, We propose a simple implementation of off-axis coherence holography with a commercial projector combined with a Sagnac radial shearing interferometer. The projector functions as a device for display and incoherent illumination of a coherence hologram, which permits reconstruction of the hologram with a generic spatially-incoherent quasi-monochromatic thermal light source. The Sagnac radial shearing interferometer, with its inherent stability of a common-path interferometer and controllable magnification introduced by variable shear, functions as a device for correlating optical fields to detect the 3-D coherence function that represents the object recorded in the coherence hologram. A set of phase-shifted Fourier transform holograms was displayed sequentially with the projector. The coherence function was detected by applying the phase-shift technique to the Sagnac radial shearing interferometer, and the object was reconstructed as the 3-D correlation map of the fields diffracted from the hologram. The technique can be applied for dispersion-free spatial coherence tomography and profilometry.
International conference proceedings, English

Theoretical and experimental investigation of statistics of spatial derivatives of Stokes parameters for polarization speckle
Shun Zhang; Paul Roulleau; Akihiro Matsuda; Mitsuo Takeda; Wei Wang
INTERFEROMETRY XV: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 7790, 77900N1-8, 2010, Peer-reviwed, The statistical properties of the spatial derivatives of the Stokes parameters for polarization speckle are investigated theoretically and experimentally. Based on the Gaussian assumption, the six-dimensional joint probability density function (p.d.f) for the derivatives of the Stokes parameters (S-1, S-2 and S-3) are all derived analytically for the first time. Subsequently, three two-dimensional p.d.f of derivatives for each Stokes parameters and the corresponding six marginal p.d.f are also given. Based on polar-interferometry, experiments have also been conducted to demonstrate the validity of the principle.
International conference proceedings, English

Experimental investigation of critical points in optical coherence function
Wei Wang; Vasilij Vasil'ev; Marat Soskin; Mitsuo Takeda
NATURE OF LIGHT: LIGHT IN NATURE III, SPIE-INT SOC OPTICAL ENGINEERING, 7782, 77820A1-7, 2010, Peer-reviwed, By using an unconventional holography, referred to as coherence holography, developed recently, we will explore the whole phase field in an optical coherence function and present the direct experimental investigation to the coherence critical points, including coherence phase saddles, coherence phase extrema and coherence phase singularities. We have observed the local phase structures around the coherence critical points, and studied the relationship between the saddles and the extrema in the optical coherence function. Some topological rules associated with the coherence critical points, such as topological sign rule governing the coherence vortices and topological index conservation during the reaction of the coherence vortices, are also investigated by experiments.
International conference proceedings, English

Vortices in generalized Stokes parameters
Rakesh Kumar Singh; Dinesh N. Naik; Hitoshi Itou; Yoko Miyamoto; Mitsuo Takeda
NATURE OF LIGHT: LIGHT IN NATURE III, SPIE-INT SOC OPTICAL ENGINEERING, 7782, 7782091-7782099, 2010, Peer-reviwed, Presence of vortices/phase singularities has been demonstrated in instantaneous generalized Stokes parameters (IGSP) of the field generated by illuminating a random phase screen with a polarization structured beam. Polarization structuring is achieved by focusing the vector beam with tilt in one of the orthogonal polarization components with respect to other. Spatially structured polarized beam is scattered by non-birefringent random phase screen placed at the focal plane of focusing lens. Field distribution of orthogonal polarization components are evaluated at the focal plane of second lens, and subsequently IGSPs are evaluated. Evaluations of the IGSPs are performed by varying one observation point r(2) with respect to a fixed reference point r(1). Distribution of phase singularities is displayed in the phase map of IGSP. These singularities disappear in the spatially averaged generalized stokes parameters.
International conference proceedings, English

Coherence holography for real-time object recording and reconstruction
D. N. Naik; T. Ezawa; Y. Miyamoto; M. Takeda
7th International Conference on Optics-photonics Design and Fabrication (ODF '10), 17-18, 2010, Peer-reviwed
International conference proceedings, English

Spatial coherence profilometry on tilted surfaces
Pavel Pavlicek; Marek Halouzka; Zhihui Duan; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 48, 34, H40-H47, Dec. 2009, Peer-reviwed, The influence of tilted surfaces on the measurement of shape by spatial coherence profilometry is investigated. Based on theoretical analysis and experimental results, the systematic measurement error caused by surface tilt is determined. The systematic measurement error depends not only on the tilt angle but also on the parameters of the experimental setup. The theoretical analysis and the experiments show the similarities and differences between spatial coherence profilometry and white-light interferometry. We also suggest the conditions to obtain correct measurements by use of spatial coherence profilometry. (C) 2009 Optical Society of America
Scientific journal, English

A Theory of Phase Singularities for Image Representation and its Applications to Object Tracking and Image Matching
Yu Qiao; Wei Wang; Nobuaki Minematsu; Jianzhuang Liu; Mitsuo Takeda; Xiaoou Tang
IEEE TRANSACTIONS ON IMAGE PROCESSING, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 18, 10, 2153-2166, Oct. 2009, Peer-reviwed, This paper studies phase singularities (PSs) for image representation. We show that PSs calculated with Laguerre-Gauss filters contain important information and provide a useful tool for image analysis. PSs are invariant to image translation and rotation. We introduce several invariant features to characterize the core structures around PSs and analyze the stability of PSs to noise addition and scale change. We also study the characteristics of PSs in a scale space, which lead to a method to select key scales along phase singularity curves. We demonstrate two applications of PSs: object tracking and image matching. In object tracking, we use the iterative closest point algorithm to determine the correspondences of PSs between two adjacent frames. The use of PSs allows us to precisely determine the motions of tracked objects. In image matching, we combine PSs and scale-invariant feature transform (SIFT) descriptor to deal with the variations between two images and examine the proposed method on a benchmark database. The results indicate that our method can find more correct matching pairs with higher repeatability rates than some well-known methods.
Scientific journal, English

Higher-dimensional entanglement effects in the detection of orbital angular momentum entangled photon pairs using hologram
Y. Miyamoto; D. Kawase; M. Takeda; K. Sasaki; S. Takeuchi
18th International Laser Physics Workshop (LPHYS '09), 557, Jul. 2009, Peer-reviwed
International conference proceedings, English

Achromatic deep nulling with a three-dimensional Sagnac interferometer
Kaito Yokochi; Alexander V. Tavrov; Jim Nishikawa; Naoshi Murakami; Lyu Abe; Motohide Tamura; Mitsuo Takeda; Takashi Kurokawa
OPTICS LETTERS, OPTICAL SOC AMER, 34, 13, 1985-1987, Jul. 2009, Peer-reviwed, A 3-D Sagnac interferometer can null out light from an on-axis source achromatically. The 3-D Sagnac interferometer can make stable and achromatic pi phase shifts, because it has a common path structure. The achromaticity of the interferometer is theoretically proved by,Jones calculus. The experimental setup is constructed, and its nulling characteristics are measured to be about 10(-6) at 5 lambda/d for green (lambda=532 nm) and red (lambda=633 nm) laser light simultaneously This interferometer Would be very useful for the direct detection of faint extrasolar planets. (C) 2009 Optical Society of America
Scientific journal, English

Polarization singularities generated by a Laguerre-Gaussian beam and a Gaussian beam
Y. Miyamoto; S. Igarashi; M. Takeda
19th International Conference on Laser Spectroscopy (ICOLS 2009), 251-252, Jun. 2009, Peer-reviwed
International conference proceedings, English

3-D coherence holography using a modified Sagnac radial shearing interferometer with geometric phase shift
Dinesh N. Naik; Takahiro Ezawa; Yoko Miyamoto; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 17, 13, 10633-10641, Jun. 2009, Peer-reviwed, A new image reconstruction scheme for coherence holography using a modified Sagnac-type radial shearing interferometer with geometric phase shift is proposed, and the first experimental demonstration of generic Leith-type coherence holography, which reconstructs off-axis 3-D objects with depth information, is presented. The reconstructed image, represented by a coherence function, can be visualized with a controllable magnification, which opens up a new possibility for a coherence imaging microscope (C) 2009 Optical Society of America
Scientific journal, English

New Tools and Materials Enabling Half-millimeter Microsurgery
N. Kuroshima; M. Takeda; dn M. Ito
5th Congress of the World Society for Reconstruction Microsurgery, 1, Jun. 2009, Peer-reviwed
International conference proceedings, English

Effect of high-dimensional entanglement of Laguerre-Gaussian modes in parametric downconversion
Daisuke Kawase; Yoko Miyamoto; Mitsuo Takeda; Keiji Sasaki; Shigeki Takeuchi
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS, OPTICAL SOC AMER, 26, 4, 797-804, Apr. 2009, Peer-reviwed, We calculate the coincidence count probabilities when the photon pairs entangled in orbital angular momentum generated via spontaneous parametric downconversion are measured by using holograms with an in-fold dislocation, considering the nonzero crystal length. We find that the coincidence probabilities related to azimuthal changes in hologram positions deviate significantly from a sinusoidal curve, which has often been assumed in simple analyses. It is found that the main cause of this effect is the high-dimensional entanglement in Laguerre-Gaussian modes. We also find that the crystal length causes the hologram positions to change for the maximum coincidence probabilities. (c) 2009 Optical Society of America
Scientific journal, English

Development of 4th-Order Nulling Coronagraphs for Partially Resolved Stars, Exoplanets and Disks: Their Formation and Diversity
N. Murakami; K. Yokochi; J. Nishikawa; M. Tamura; N. Baba; R. Uemura; N. Hashimoto; L. Abe; A. V. Tavrov; T. Kurokawa; M. Takeda
The 2nd Subaru International Conference, 1, Mar. 2009, Peer-reviwed
International conference proceedings, English

Coherence holography: A thought on synthesis and analysis of optical coherence fields
Mitsuo Takeda; Wei Wang; Dinesh N. Naik
Fringe 2009 - 6th International Workshop on Advanced Optical Metrology, Springer-Verlag Berlin Heidelberg, 14-21, 2009, Peer-reviwed
International conference proceedings, English

Statistics of polarization speckle: Theory versus experiment
Wei Wang; Steen G. Hanson; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, 7388, 2009, Peer-reviwed, In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters. © 2009 Copyright SPIE - The International Society for Optical Engineering.
International conference proceedings, English

Development of Fourth-order Nulling Coronagraphs for Partially Resolved Stars
N. Murakami; K. Yokochi; J. Nishikawa; M. Tamura; N. Baba; R. Uemura; N. Hashimoto; L. Abe; A. V. Tavrov; T. Kurokawa; M. Takeda
EXOPLANETS AND DISKS: THEIR FORMATION AND DIVERSITY, AMER INST PHYSICS, 1158, 397-398, 2009, Peer-reviwed, We present our recent progress in development of two novel coronagraphs; an eight-octant phase-mask (8OPM) coronagraph and a tandem common-path achromatic interfero-coronagraph (TCP-AIC). These methods have fourth-order responses to tip-tilt errors, and can realize deep stellar suppression for partially resolved stars. We report principles, numerical simulations and laboratory demonstrations of the proposed methods.
International conference proceedings, English

Coronagraph Methods on Precise Wavefront Compensation (UNI-PAC) and Deep Achromatic Nulling
J. Nishikawa; K. Yokochi; N. Murakami; L. Abe; T. Kotani; M. Tamura; T. Kurokawa; A. V. Tavrov; M. Takeda
EXOPLANETS AND DISKS: THEIR FORMATION AND DIVERSITY, AMER INST PHYSICS, 1158, 365-+, 2009, Peer-reviwed, We present our recent progress in the development of two novel coronagraphs: an eight-octant phase-mask (8OPM) coronagraph and a tandem common-path achromatic interfero-coronagraph (TCP-AIC). These methods have 4th-order responses to tip-tilt errors, and can realize deep stellar suppressions for partially resolved stars. We report principles, numerical simulations and laboratory demonstrations of the proposed methods.
International conference proceedings, English

3-D coherence holography using a modified Sagnac radial shearing interferometer with geometric phase shift
Dinesh N. Naik; Takahiro Ezawa; Yoko Miyamoto; Mitsuo Takeda
HOLOGRAPHY: ADVANCES AND MODERN TRENDS, SPIE-INT SOC OPTICAL ENGINEERING, 7358, 735808, 2009, Peer-reviwed, A new image reconstruction scheme for coherence holography using a modified Sagnac-type radial shearing interferometer with geometric phase shift is proposed and experimentally demonstrated. The reconstruction of off-axis objects placed at different depths makes this proposed technique the most generic one. A reconstructed image, represented by a coherence function, can be visualized with a controllable magnification, which opens up a new possibility for a coherence imaging microscope.
International conference proceedings, English

High dynamic range optical system for direct detection of exo-planets by unbalanced nulling interferometer and adaptive optics
K. Yokochi; J. Nishikawa; N. Murakami; L. Abe; T. Kotani; M. Tamura; A. V. Tavrov; M. Takeda; T. Kurokawa
2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5, IEEE, 489-+, 2009, Peer-reviwed, We proposed a pre-optical system for a stellar coronagraph to reduce stellar speckle noise for direct detection of exo-planets. It consists of an unbalanced nulling interferometer (UNI) and phase and amplitude correction (PAC) system. We demonstrated a magnification of a wavefront aberration (from lambda/138 to lambda/21 rms) by the UNI, and correction of the aberration to lambda/21 rms by the PAC. We also evaluated nulling performance of a coronagraph with the UNI-PAC system. (C) 2008 Optical Society of America
International conference proceedings, English

Phase analysis error reduction in the Fourier transform method using a virtual interferogram
H. Toba; Z. Liu; S. Udagawa; N. Fujiwara; S. Nakayama; T. Gemma; M. Takeda
Proceedings of SPIE - The International Society for Optical Engineering, 7389, 10.1-9, 2009, Peer-reviwed, We propose a new method for reducing ripple phase errors in the fringe analysis by the Fourier transform method. Object profiles obtained by the conventional Fourier transform method tend to have ripple errors at the boundary edges of the fringe pattern. The shape of these ripple phase errors are found to have certain systematic relations to low order components of the phase and intensity distributions, which can be modeled by polynomials (such as Zernike polynomials). We estimate the systematic ripple errors by analyzing a virtual interferogram which is numerically created with models of the intensity and the phase. Starting from a rough initial guess, the virtual interferogram is sequentially improved by an iterative algorithm. Results of simulations and experiments that demonstrate the validity of the proposed method are presented. © 2009 SPIE.
International conference proceedings, English

Real-time coherence holography
Dinesh N. Naik; Takahiro Ezawa; Yoko Miyamoto; Mitsuo Takeda
Fringe 2009 - 6th International Workshop on Advanced Optical Metrology, Springer-Verlag Berlin Heidelberg, 28-33, 2009, Peer-reviwed
International conference proceedings, English

Fourier-transform method with high accuracy by use of iterative technique narrowing the spectra of a fringe pattern
S. Nakayama; H. Toba; N. Fujiwara; T. Gemma; M. Takeda
Fringe 2009 - 6th International Workshop on Advanced Optical Metrology, Springer-Verlag Berlin Heidelberg, 106-111, 2009, Peer-reviwed
International conference proceedings, English

Manipulation of optical quNits using geometrical phase
D. Kawase; Y. Miyamoto; M. Takeda; K. Sasaki; S. Takeuchi
International Symposium on Physics of of Quantum Technology, 37, Nov. 2008
International conference proceedings, English

Coherence holography using Sagnac radial shearing interferometer with geometric phase shift
D. N. Naik; T. Ezawa; Y. Miyamoto; M. Takeda
Japan Taiwan Bilateral Science and Technology Symposium, Frontiers in Functional Optics, 116-117, Nov. 2008, Peer-reviwed
International conference proceedings, English

Coherence and polarization of electromagnetic beams modulated by random phase screens and their changes through complex ABCD optical systems
Steen G. Hanson; Wei Wang; Michael L. Jakobsen; Mitsuo Takeda
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 25, 9, 2338-2346, Sep. 2008, Peer-reviwed, The change of coherence and polarization of an electromagnetic beam modulated by a random anisotropic phase screen passing through any optical system is found within the framework of complex ABCD-matrix theory This means that the formalism can treat. imaging and Fourier transform and free-space optical systems, as well as fractional Fourier transform systems, with finite-size limiting apertures of Gaussian transmission shape. Thus, the current paper shall be considered as a continuation, extension, and generalization of a previous work by Shirai and Wolf [J. Opt. Soc. Am. A 21, 1907 (2004)]. It will be shown that the inclusion of apertures in the optical system strongly influences not only the propagation of spatial coherence but also the degree of polarization of a propagating field. Analytical expressions of coherence and polarization propagation will be given in terms of the matrix elements for any complex optical system. (C) 2008 Optical Society of America.
Scientific journal, English

Achromatic interfero-coronagraph with two common-path interferometers in tandem
Alexander V. Tavrov; Jun Nishikawa; Motohide Tamura; Lyu Abe; Kaito Yokochi; Takashi Kurokawa; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 47, 27, 4915-4926, Sep. 2008, Peer-reviwed, To attain deeper nulling for an extended incoherent star disk a scheme for an achromatic interfero-coronagraph, incorporating two common-path interferometers in tandem, is proposed. Analytical and numerical predictions of the performance, which are in reasonably good agreement, are presented. The predicted performance improvement, by using two interferometers in tandem, is demonstrated by a preliminary experiment. A star coronagraph based on the proposed technique has the possibility to reach a 10(-10) achromatic nulling contrast for an almost 10(-2) lambda/D effective source size. (C) 2008 Optical Society of America
Scientific journal, English

Constellation of phase singularities in a speckle-like pattern for optical vortex metrology applied to biological kinematic analysis
Wei Wang; Yu Qiao; Reika Ishijima; Tomoaki Yokozeki; Daigo Honda; Akihiro Matsuda; Steen G. Hanson; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 16, 18, 13908-13917, Sep. 2008, Peer-reviwed, A novel technique for biological kinematic analysis is proposed that makes use of the pseudophase singularities in a complex signal generated from a speckle-like pattern. In addition to the information about the locations and the anisotropic core structures of the pseudophase singularities, we also detect the spatial structures of a cluster of phase singularities, which serves as a unique constellation characterizing the mutual position relation between the individual pseudophase singularities. Experimental results of in vivo measurements for a swimming fish along with its kinematic analysis are presented, which demonstrate the validity of the proposed technique. (c) 2008 Optical Society of America.
Scientific journal, English

Observing quantum correlation of photons in Laguerre-Gauss modes using the Gouy phase
Daisuke Kawase; Yoko Miyamoto; Mitsuo Takeda; Keiji Sasaki; Shigeki Takeuchi
PHYSICAL REVIEW LETTERS, AMER PHYSICAL SOC, 101, 5, 050501, Aug. 2008, Peer-reviwed, The effect of the Gouy phase, which is one of the geometrical phases of photons, is observed through quantum correlation in Laguerre-Gaussian (LG) modes. In an experiment, the relative phase of two different LG modes of measurement basis states is manipulated via the Gouy phase, and the observed coincidence count rates agree well with theoretical predictions. This result suggests that the Gouy phase can be used as a new tool to manipulate multidimensional photonic quantum states.
Scientific journal, English

Birth and evolution of orbital angular coherence momentum associated with coherence vortex
W. Wang; M. Takeda
Photon 08, 24-25, Aug. 2008, Peer-reviwed
International conference proceedings, English

Diagnosis of polarization speckle based on frequency-multiplex Fourier transform method
W. Wang; A. Matsuda; S. G. Hanson; M. Takeda
Photon 08, 49-50, Aug. 2008, Peer-reviwed
International conference proceedings, English

Pseudo Stokes vector correlation for micro-displacement measurement
W. Wang; R. Ishijima; A. Matsuda; S. G. Hanson; M. Takeda
International Conference on Full-field Measurement Techniques and Their Applications in Experimental Solid Mechanics, 1, Jul. 2008, Peer-reviwed
International conference proceedings, English

Optical vortex metrology for nano and bio measurements
W. Wang; S. G. Hanson; M. Takeda
The Rank Prized Fund Mini-symposium on optical aspects of non-destructive testing, 1, May 2008, Peer-reviwed
International conference proceedings, English

Experimental investigation of the singular phenomena in statistical optical fields
Wei Wang; Mitsuo Takeda
NATURE OF LIGHT: LIGHT IN NATURE II, SPIE-INT SOC OPTICAL ENGINEERING, 7057, 2008, Peer-reviwed, This paper is a review and extension of our recent work on three types of singular optical phenomena in statistical optical fields, including phase singularities (optical vortices) in laser speckle fields. polarization singularities in polarization speckle, and coherence vortices in optical coherence functions. For the generation and detection of these unique singular optical phenomena, different optical setups have been introduced. Some geometric structures and statistics associated with singularities are also investigated by experiments.
International conference proceedings, English

Coherence holography and singular optical coherence
Mitsuo Takeda; Wei Wang
OPTICS AND PHOTONICS FOR INFORMATION PROCESSING II, SPIE-INT SOC OPTICAL ENGINEERING, 7072, 2008, Peer-reviwed, The principle of unconventional holography, called coherence holography, is reviewed with particular emphasis on the formal analogy between an optical field and its coherence function, which gives a clue for developing a new technique for synthesizing singular optical coherence. We present experimental demonstrations of generic coherence vortices generated by coherence holography, and show an experimental evidence of an angular coherence momentum created by coherence currents circulating around the core of the coherence vortex and a conservation law of coherence currents.
International conference proceedings, English

Achromatic characteristics in 3-D Sagnac interferometer based on geometric phase shift
K. Yokochi; A. V. Tavrov; J. Nishikawa; L. Abe; M. Tamura; M. Takeda; T. Kurokawa
2008 CONFERENCE ON LASERS AND ELECTRO-OPTICS & QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE, VOLS 1-9, IEEE, 720-+, 2008, Peer-reviwed, A three-dimensional Sagnac interferometer based on geometric phase is constructed and its nulling characteristics are measured to be 5E-5 for green and red laser light simultaneously. (C) 2008 Optical Society of America
International conference proceedings, English

Coherence vortices, coherence current, and the conservation laws in coherence dynamics
Wei Wang; Steen G. Hanson; Mitsuo Takeda
8TH INTERNATIONAL CONFERENCE ON CORRELATION OPTICS, SPIE-INT SOC OPTICAL ENGINEERING, 7008, 2008, Peer-reviwed, We review the principle of coherence dynamics proposed recently to explain the origin of coherence vortices, which are the phase singularities in a complex coherence function. Some properties associated with coherence vortex, such as the coherence Current describing the circular contrast flow close to a vortex core and conservation laws of coherence, are investigated both theoretically and experimentally.
International conference proceedings, English

Optical vortex metrology: Are phase singularities foes or friends in optical metrology?
Mitsuo Takeda; Wei Wang; Steen G. Hanson; Yoko Miyamoto
8TH INTERNATIONAL CONFERENCE ON CORRELATION OPTICS, SPIE-INT SOC OPTICAL ENGINEERING, 7008, 2008, Peer-reviwed, We raise an issue whether phase singularities are foes or friends in optical metrology, and give an answer by introducing the principle and applications of a new technique which we recently proposed for displacement and flow measurements. The technique is called optical vortex metrology because it makes use of the unique characteristics of phase singularities as markers or tracers for the displacement and flow measurements. The phase singularities are created in the complex signal representation of a speckle-like random pattern, which is generated by means of a vortex filer operating a Riesz or Laguerre-Gauss transform to the random pattern.
International conference proceedings, English

Precision interferometry for measuring wavefronts of multi-wavelength optical pickups
Zongtao Ge; Takayuki Saito; Minoru Kurose; Hideo Kanda; Kazuhisa Arakawa; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 16, 1, 133-143, Jan. 2008, Peer-reviwed, A novel wavefront measurement interferometer is developed that enables the user to evaluate the wavefronts of multi-wavelength optical pickups. In this interferometer, instead of transparent pinholes used in Mach-Zehnder interferometers, reflection dot pinhole mirrors are used to generate reference wavefronts for different wavelengths which make the optical system very flexible and simple compared with those using transparent pinholes. The interferometer is designed to operate at wavelengths of 405nm, 650nm and 780nm over an NA range of up to 0.95, which is very difficult to realize when transparent pinholes are used for generating reference wavefronts. The three-beam problem is solved and the optics of the interferometer is simplified by employing a software filter instead of using spatial filters in the optics of the interferometer. The instrument has an equal optical path length that enables the user to measure pickups with a very short coherence length. A new method by which asymmetric aberration components, such as astigmatic and coma aberrations, can be calibrated by rotating the measured lens with 90 and 180 degrees is proposed and the calibration results are verified by using a high precision reference point source. System accuracy is also evaluated by comparing with the measurement results obtained by commercial Fizeau type interferometer and a good agreement is achieved. (c) 2008 Optical Society of America.
Scientific journal, English

Vortex sheets in optical and coherence fields
Wei Wang; Kentaro Chiba; Steen G. Hanson; Mitsuo Takeda
COMPLEX LIGHT AND OPTICAL FORCES II, SPIE-INT SOC OPTICAL ENGINEERING, 6905, 690506-690513, 2008, Peer-reviwed, Instead of the well-known line type of phase singularities in optical and coherence fields, we introduce a new concept of what we call Vortex Sheet into singular optics. This vortex sheet has a surface topological structure, on which the phase of the scalar optical or the coherence fields becomes undefined with zero amplitude. Some properties related to these surface topological deformations, such as optical and coherence surface flow, are investigated both theoretically and experimentally for the first time.
International conference proceedings, English

The spatial degree of polarization and the first-order statistical properties of polarization speckle
Wei Wang; Akthiro Matsuda; Steen G. Hanson; Mitsuo Takeda
INTERFEROMETRY XIV: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 7063, 70630B1-B9, 2008, Peer-reviwed, In analogy with the degree of polarization used widely for the description of partially polarized thermal light, we introduced a new concept of the spatial degree of polarization to characterize the statistical properties of the polarization speckle with its polarization states fluctuating in space. As a function of the spatial degree of polarization, the first order statistics of the polarization speckle are studied theoretically, and the corresponding probability density functions of the Stokes parameters are measured experimentally by a polarization interferometer to demonstrate the validity of the principle.
International conference proceedings, English

Detection of orbital angular momentum superposition photon states with hologram and path interferometer
Y. Miyamoto; M. Takeda; D. Kawase; S. Takeuchi; K. Sasaki; A. Wada
International Symposium on Coherent Optical Science, 16, Dec. 2007
International conference proceedings, English

Development status of EUV wavefront metrology system (EWMS)
K. Murakami; K. Sugisaki; M. Okada; K. Ohtaki; Z. Yucong; Z. Liu; J. Saito; C. Ouchi; S. Kato; M; Hasegawa, T; Hasegawa; H. Yokota; M. Niibe; M. Takeda
2007 International Extreme Ultraviolet Lithography (EUVL) Symposium, ME-01, Dec. 2007, Peer-reviwed
International conference proceedings, English

Common-path achromatic interferometer-coronagraph: Images from a breadboard demonstrator
Alexander V. Tavrov; Jun Nishikawa; Motohide Tamura; Lyu Abe; Kaito Yokochi; Takashi Kurokawa; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 46, 28, 6885-6895, Oct. 2007, Peer-reviwed, A three-dimensional common-path interferometer is proposed, which can achromatically null out an on-axis source while maintaining the detectability of an off-axis source. A geometric phase in the three-dimensional interferometer introduces an achromatic pi-phase shift to the light from the on-axis source, such that destructive interference nulls out the axial light at one of the ports of the interferometer. Light from the off-axis source, which is exempt from destructive interference, comes out from both ports with equal intensity. The common-path scheme makes the system highly immune to environmental disturbances. In the described experiment, a 6 X 10(-6) peak-to-peak nulling contrast was obtained. (c) 2007 Optical Society of America.
Scientific journal, English

Separation of spin and orbital angular coherence momenta in the second-order coherence theory of vector electromagnetic fields
Wei Wang; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 32, 18, 2656-2658, Sep. 2007, Peer-reviwed, In analogy with the separation of the total optical angular momentum into a spin and an orbital part in electrodynamics, we introduce a new concept of spin and orbital angular coherence momenta into the general coherence theory of vector electromagnetic fields. The properties of the newly introduced spin and orbital angular coherence momenta are investigated through the decomposition of the total coherence angular momentum into the sum of these two components, and their separate conservations have been derived for what is believed to be the first time. (c) 2007 Optical Society of America.
Scientific journal, English

Resolution and noise factor of distance measurement using two-photon absorption process in photodetector
Yosuke Tanaka; Tatsutoshi Shioda; Mitsuo Takeda; Takashi Kurokawa
Japanese Journal of Applied Physics, INSTITUTE OF PURE AND APPLIED PHYSICS, 46, 8, 5331-5337, Aug. 2007, Peer-reviwed, In this paper, we investigate the resolution, accuracy, and noise factor of distance measurement using intensity-modulated light and a photodetector with two-photon absorption (TPA) characteristics. Distance resolution and measurement accuracy are clarified theoretically and experimentally in terms of the sweeping range and the scanning step of the intensity-modulation frequency. The theory of accuracy improvement by signal processing known as the "Fourier transform method" is experimentally confirmed for the first time. The influence of a photodetector's temperature on measurement resolution is also made clear by the experiments. A high resolution is achieved by controlling the photodetector at a low temperature, which is explained from the temperature dependence of TPA sensitivity in the photodetector. In addition to these investigations, we discuss the advantage of the TPA-based distance measurement over other conventional methods such as optical time domain reflectometry from the viewpoints of cost and measurement performance.
Scientific journal, English

Extension of distance measurement range in a sinusoidal wavelength-scanning interferometer using a liquid-crystal wavelength filter with double feedback control
Osami Sasaki; Akihiro Saito; Takamasa Suzuki; Mitsuo Takeda; Takashi Kurokawa
APPLIED OPTICS, OPTICAL SOC AMER, 46, 23, 5800-5804, Aug. 2007, Peer-reviwed, The optical path difference (OPD) and amplitude of a sinusoidal wavelength scanning (SWS) are controlled with a double feedback control system in an interferometer, so that a ruler marking every wavelength and a ruler with scales smaller than a wavelength are generated. These two rulers enable us to measure an OPD longer than a wavelength. A liquid-crystal Fabry-Perot interferometer (LC-FPI) is adopted as a wavelength-scanning device, and double sinusoidal phase modulation is incorporated in the SWS interferometer. Because of a high resolution of the LC-FPI, the upper limit of the measurement range can be extended to 280 mu m by the use of the phase lock where the amplitude of the SWS is doubled in the feedback control. The ruler marking every wavelength is generated between 80 mu m and 280 mu m, and distances are measured with a high accuracy of the order of a nanometer in real time. (c) 2007 Optical Society of America.
Scientific journal, English

Poincare sphere representation for the anisotropy of phase singularities and its applications to optical vortex metrology for fluid mechanical analysis
Wei Wang; Mark R. Dennis; Reika Ishijima; Tomoaki Yokozeki; Akihiro Matsuda; Steen G. Hanson; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 15, 17, 11008-11019, Aug. 2007, Peer-reviwed, A new technique for fluid mechanics measurement is proposed that makes use of the elliptic anisotropy of phase singularities in the complex signal representation of a speckle-like pattern. Based on the formal analogy between the polarization field of a vector wave and the gradient field of the complex signal, the Poincare sphere representation has been used to characterize the phase singularities that serve as unique fingerprints attached to the seeding particles moving with the flow. Experimental results for flow velocity and acceleration measurement are presented that demonstrate the validity of the proposed optical vortex metrology for fluid mechanics measurement.
(c) 2007 Optical Society of America.
Scientific journal, English

Experimental verification of entanglement in LG modes using holograms and path interferometer
D. Kawase; S. Takeuchi; K. Sasaki; A. Wada; Y. Miyamoto; M. Takeda
Topology and Singularity in Optical Physics, 44, Jul. 2007
International conference proceedings, English

The spatial structures of pseudophase singularities in the analytic signal representation of a speckle pattern and their application to biological kinematic analysis
W. Wang; Y. Qiao; R. Ishijima; T. Yokozeki; D. Honda; A. Matsuda; S. G. Hanson; M. Takeda
International Conference on Experimental Mechanics, ICEM 13, 1, Jul. 2007, Peer-reviwed
International conference proceedings, English

Aberration evaluation of alignment optics in lithographic tools by use of a step-height structure highly sensitive to the asymmetry of an optical image
Hideki Ina; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 46, 17, 3485-3492, Jun. 2007, Peer-reviwed, To satisfy the increasing demand for extremely tight overlay accuracy in semiconductor manufacturing processes, all the measurement error factors in alignment systems and overlay measurement tools need be identified and eliminated. The principle of most alignment systems is based on image processing of target marks on the wafer under bright-field illumination. Although the phenomenon that the sensitivity to the alignment error varies with the step height (SH) of the mark has been known and used for evaluating the performance of the alignment optics, no investigation has been made into the origin and the physical mechanism of the phenomenon. We propose a simplified optical model that can account for the origin of the asymmetric image and clarify its relation to the SHs. The model is validated with simulation and experimental results. The improved performance of an alignment system using marks with optimally designed SHs is demonstrated. (C) 2007 Optical Society of America.
Scientific journal, English

Low speckle noise coronagraph with UNI+PAC
T. Kotani; J. Nishikawa; K. Yokochi; N. Murakami; L. Abe; M. Tamura; T. Kurokawa; A. Tavrov; M. Takeda
Spirit of Lyot 2007, The Direct Detection of Planets and Circumstellar Disks in the 21st Century, 52, Jun. 2007, Peer-reviwed
International conference proceedings, English

Precise wavefront correction with unbalanced nulling interferometer for direct detection of exo-planet
Kaito Yokochi; Jun Nishikawa; Naoshi Murakami; Lyu Abe; Takayuki Kotani; Motohide Tamura; Takashi Kurokawa; Alexander V. Tavrov; Mitsuo Takeda
2007 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, VOLS 1-4, IEEE, 393-+, 2007, Peer-reviwed, We propose a pre-optical system for a stellar coronagraph to reduce the speckle noise. It consists of an (amplitude-) Unbalanced Nulling Interferometer (UNI) and Phase and Amplitude Correction (PAC) with two deformable mirrors. We have demonstrated that an initial wavefront error of lambda/82 is 3.9 times magnified to lambda/22 by the UNI.
International conference proceedings, English

Accuracy of distance measurement based on two-photon absorption of Si-photodetector
Tatsuya Oiwa; Tatsutoshi Shioda; Yosuke Tanaka; Mitsuo Takeda; Takashi Kurokawa
Optics InfoBase Conference Papers, 2007, We have successfully measured a space distance with the accuracy of less than 10-5 based on TPA process in a silicon photodetector. The two signal processing technologies including the Fourier transform method and the curve fitting method were investigated. © CLEO Pacific Rim 2007.
International conference proceedings

Accuracy of distance measurement based on two-photon absorption of Si-photodetector
Tatsuya Oiwa; Tatsutoshi Shioda; Yosuke Tanaka; Mitsuo Takeda; Takashi Kurokawa
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest, 2007, We have successfully measured a space distance with the accuracy of less than 10-5 based on TPA process in a· silicon photodetector. The two signal processing technologies including the Fourier transform method and the curve fitting method were investigated.
International conference proceedings

Optical vortex metrology: Displacement and flow measurements with phase singularities
Mitsuo Takeda; Wei Wang; Steen G. Hanson; Yoko Myamoto
6TH INTERNATIONAL WORKSHOP ON INFORMATION OPTICS (WIO '07), AMER INST PHYSICS, 949, 185-+, 2007, Peer-reviwed, We review the principle and the applications of a new technique which we recently proposed for displacement and flow measurements. The technique is called optical vortex metrology because it makes use of phase singularities in the complex signal as markers or tracers, which are generated by a vortex filer that performs a Riesz or Laguerre-Gauss transform operation to a speckle-like random pattern.
International conference proceedings, English

Spatial coherence profilometry
Pavel Pavlicek; Zhihui Duan; Mitsuo Takeda
15TH CZECH-POLISH-SLOVAK CONFERENCE ON WAVE AND QUANTUM ASPECTS OF CONTEMPORARY OPTICS, SPIE-INT SOC OPTICAL ENGINEERING, 6609, (16-1)-(16-7), 2007, Peer-reviwed, Spatial coherence profilometry is a method for measurement of the geometrical form of objects. In addition to the two lateral coordinates x and y, it measures the longitudinal coordinate z. In this way the complete 3D description of the object's surface is acquired. The main piece of the presented method is a Michelson interferometer illuminated by a monochromatic spatially extended light source. The surface of the object whose geometrical form should be measured is used as one mirror of the Michelson interferometer. By moving of the measured object along the optical axis, the intereference is observable only if the object's surface occurs in the vicinity of the so-called reference plane. The reference plane is given by the position of the object mirror when the Michelson interferometer is balanced. The described effect follows from the form of the spatial coherence function originated by the spatially extended light source. If the intensity at the output of the interferometer is recorded as a function of the position of the measured object, a typical correlogram arises. This correlogram is similar to that known with white-light interferometry. From the maximum of the correlogram, the z coordinate of the object's surface can be determined. Usually a CCD camera is used as the detector at the output of the Michelson interferometer. Then z coordinates of many surface points are parallel measured in the course of one measurement procedure and the 3D description of the object's surface is acquired. The scanning in the lateral direction is not necessary. Thus the described method provides a spatial coherence analogy to white-light interferometry which is based on temporal coherence. Unlike white-light interferometry, the described method does not require a broadband light source, the interferometer is illuminated by a monochromatic light source, usually a laser.
International conference proceedings, English

Spatial coherence profilometry
Pavel Pavlicek; Zhihui Duan; Mitsuo Takeda
15TH CZECH-POLISH-SLOVAK CONFERENCE ON WAVE AND QUANTUM ASPECTS OF CONTEMPORARY OPTICS, SPIE-INT SOC OPTICAL ENGINEERING, 6609, (16-1)-(16-7), 2007, Peer-reviwed, Spatial coherence profilometry is a method for measurement of the geometrical form of objects. In addition to the two lateral coordinates x and y, it measures the longitudinal coordinate z. In this way the complete 3D description of the object's surface is acquired. The main piece of the presented method is a Michelson interferometer illuminated by a monochromatic spatially extended light source. The surface of the object whose geometrical form should be measured is used as one mirror of the Michelson interferometer. By moving of the measured object along the optical axis, the intereference is observable only if the object's surface occurs in the vicinity of the so-called reference plane. The reference plane is given by the position of the object mirror when the Michelson interferometer is balanced. The described effect follows from the form of the spatial coherence function originated by the spatially extended light source. If the intensity at the output of the interferometer is recorded as a function of the position of the measured object, a typical correlogram arises. This correlogram is similar to that known with white-light interferometry. From the maximum of the correlogram, the z coordinate of the object's surface can be determined. Usually a CCD camera is used as the detector at the output of the Michelson interferometer. Then z coordinates of many surface points are parallel measured in the course of one measurement procedure and the 3D description of the object's surface is acquired. The scanning in the lateral direction is not necessary. Thus the described method provides a spatial coherence analogy to white-light interferometry which is based on temporal coherence. Unlike white-light interferometry, the described method does not require a broadband light source, the interferometer is illuminated by a monochromatic light source, usually a laser.
International conference proceedings, English

Fluid mechanics measurement based on the anisotropic core structure of pseudophase singularities in analytic signal representation of speckle pattern
Wei Wang; Mark R. Dennis; Reika Ishijima; Tomoaki Yokozeki; Akihiro Matsuda; Steen G. Hanson; Mitsuo Takeda
OPTICAL MEASUREMENT SYSTEMS FOR INDUSTRIAL INSPECTION V, PTS 1 AND 2, SPIE-INT SOC OPTICAL ENGINEERING, 6616, 66160W1-6616W8, 2007, Peer-reviwed, A new technique for fluid mechanics measurement is proposed that makes use of pseudophase singularities in an analytic signal representation of a speckle-like pattern generated by a Laguerre-Gauss filter operation. Based on the formal analogy between the polarization of the vector wave and the gradient field for the complex analytic signal, a set of Stokes-like parameters have been applied for the description of the anisotropic core structure of the pseudophase singularities, which serves as unique fingerprints attached to the seeding particles moving with the flow. Experimental results for flow velocity and acceleration measurement are presented that demonstrate the validity of the proposed optical vortex metrology for fluid mechanics measurement.
International conference proceedings, English

Decomposition of total angular coherence momentum in vectorial coherence theory of electromagnetic fields
Wei Wang; Mitsuo Takeda
6TH INTERNATIONAL WORKSHOP ON INFORMATION OPTICS (WIO '07), AMER INST PHYSICS, 949, 293-294, 2007, Peer-reviwed, In analogy to classical angular momentum in electrodynamics, we introduce a new concept of spin and orbital coherence momenta into the general coherence theory of vector electromagnetic fields. On the basis of the decomposition of the total angular coherence momentum into the sum of two terms, some properties related to the newly introduced spin and orbital coherence momenta are also investigated for the first time.
International conference proceedings, English

Coherence vortex with orbital angular coherence momentum and wave-particle duality in correlation function - art. no. 66640M
Wei Wang; Mitsuo Takeda
NATURE OF LIGHT: WHAT ARE PHOTONS?, SPIE-INT SOC OPTICAL ENGINEERING, 6664, M6640-M6640, 2007, Peer-reviwed, Under the paraxial approximation for the propagation of vectorial coherence function, we made a theoretical investigation into the mechanism of the orbital angular coherence momentum associated with a coherence vortex. By controlling the irradiance distribution of an extended quasi-monochromatic spatially incoherent source with a spatial light modulator, we examined the phase structure of coherence function and investigated the birth and evolution of the orbital angular coherence momentum. Some properties related to the fractional coherence vortex, such as a wave particle-like duality of coherence function, are also investigated both theoretically and experimentally for the first time.
International conference proceedings, English

Dispersion-free optical coherence depth sensing with a spatial frequency comb generated by an angular spectrum modulator
Zhihui Duan; Yoko Miyamoto; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 14, 25, 12109-12121, Dec. 2006, Peer-reviwed, As an alternative to the conventional optical frequency comb technique, a spatial frequency comb technique is proposed for dispersion-free optical coherence depth sensing. Instead of generating an optical frequency comb over a wide range of time spectrum, we generate a spatial frequency comb by modulating the incident angle of a monochromatic plane wave with a spatial light modulator (SLM). The use of monochromatic light combined with the SLM enables dispersion-free depth sensing that is free from mechanical moving components. (c) 2006 Optical Society of America
Scientific journal, English

Spatial coherence shaping: A new optical design in coherence domain
W. Wang; Z. Duan; S. G. Hanson; M. Takeda
5th International Conference on Optics-photonics Design and Fabrication, ODF'06, 169-170, Dec. 2006, Peer-reviwed
International conference proceedings, English

Coronagraph experiments with dynamic range absorption by pre-optics
J. Nishikawa; N. Murakami; L. Abe; T. Kotani; M. Tamura; K. Yokochi; T Kurokwa; A. Tavrov; M. Takeda
4th International TPF/Darwin Workshop, 1, Nov. 2006, Peer-reviwed
International conference proceedings, English

Optical vortex metrology based on the core structures of phase singularities in Laguerre-Gauss transform of a speckle pattern
Wei Wang; Tomoaki Yokozeki; Reika Ishijima; Mitsuo Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 14, 22, 10195-10206, Oct. 2006, Peer-reviwed, A new technique for displacement measurement is proposed that makes use of phase singularities in the complex signal generated by a Laguerre-Gauss filter operation applied to a speckle pattern. The core structures of phase singularities are used as unique fingerprints attached to the object surface, and the displacement is determined by tracing the movement of registered phase singularities with their correspondence being identified by the fingerprints. Experimental results for translational and rotational displacement measurements are presented that demonstrate large dynamic range and high spatial resolution of the proposed optical vortex metrology. (c) 2006 Optical Society of America
Scientific journal, English

Two-wavelength Talbot effect and its application for three-dimensional step-height measurement
Dalip Singh Mehta; Satish Kumar Dubey; Chandra Shakher; Mitsuo Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 45, 29, 7602-7609, Oct. 2006, Peer-reviwed, The phenomenon of Talbot self-image shift by changing the wavelength of the illuminating light is described and demonstrated experimentally. A periodic grating is illuminated by light with wavelengths lambda(1) and lambda(2) generated by two lasers, and the Talbot self-images are recorded along the longitudinal direction at individual wavelengths. The Talbot self-image shift due to the change in the wavelength of light is implemented for the measurement of the three-dimensional step height of a large discontinuous object without any phase ambiguity problem. Fourier-transform fringe analysis was used to determine the maximum contrast of the high-visibility bands for the measurement of the step height of the object. The main advantages of the proposed system are nonmechanical scanning, high stability because of its common path geometry, compactness, and a wide range of measurement as compared to interferometric three-dimensional profilers. (c) 2006 Optical Society of America.
Scientific journal, English

Coherence Momentum in Second-Order Vectorial Coherence Theory of Stationary Electromagnetic Fields
W. Wang; M. Takeda
Frontiers in Optics 2006, OSA Annual Meeting, JWD43, Oct. 2006, Peer-reviwed
International conference proceedings, English

Experimental observation of the evolution of the fractional topological phase for a coherence function
W. Wang; Z. Duan; S. G. Hanson; M. Takeda
Frontiers in Optics 2006, OSA Annual Meeting, PDP-FB1, Oct. 2006, Peer-reviwed
International conference proceedings, English

Linear and angular coherence momenta in the classical second-order coherence theory of vector electromagnetic fields
Wei Wang; Mitsuo Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 31, 17, 2520-2522, Sep. 2006, Peer-reviwed, A new concept of vector and tensor densities is introduced into the general coherence theory of vector electromagnetic fields that is based on energy and energy-flow coherence tensors. Related coherence conservation laws are presented in the form of continuity equations that provide new insights into the propagation of second-order correlation tensors associated with stationary random classical electromagnetic fields. (c) 2006 Optical Society of America.
Scientific journal, English

Complex amplitude correlations of dynamic laser speckle in complex ABCD optical systems
Wei Wang; Steen G. Hanson; Mitsuo Takeda
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 23, 9, 2198-2207, Sep. 2006, Peer-reviwed, Within the framework of complex ABCD-matrix theory, exact theoretical expressions are derived for the space-time-lagged cross-covariance functions of the fields valid for arbitrary (complex) ABCD-optical systems, i.e., systems that include Gaussian-shaped apertures and partially developed speckle. Specifically, we show and discuss the results for the three generic systems, i.e., free-space propagation, Fourier transform configuration, and imaging. To cope with various surface structures of varying rms surface heights, we apply two models in addition to employing the usual model for surfaces giving rise to fully developed speckle. The theoretical results found for free-space propagation are supported by interferometrically obtained data. (c) 2006 Optical Society of America.
Scientific journal, English

Coherence current, coherence vortex, and the conservation law of coherence
Wei Wang; Mitsuo Takeda
PHYSICAL REVIEW LETTERS, AMER PHYSICAL SOC, 96, 22, Jun. 2006, Peer-reviwed, Introducing scalar and vector densities for a mutual coherence function, we present a new conservation law for optical coherence of scalar wave fields in the form of a continuity equation. This coherence conservation law provides new insights into topological phenomena for the complex coherence function. Some properties related to the newly introduced coherence vector density, such as a circulating coherence current associated with a coherence vortex, are investigated both theoretically and experimentally for the first time.
Scientific journal, English

Phase-crossing algorithm for white-light fringes analysis
ME Pawlowski; Y Sakano; Y Miyamoto; M Takeda
OPTICS COMMUNICATIONS, ELSEVIER SCIENCE BV, 260, 1, 68-72, Apr. 2006, Peer-reviwed, The phase-crossing algorithm is proposed for white-light interferometry, which uses the multi-color phase information of spectrally decomposed interferograms recorded simultaneously with color-sensitive image sensors. The location of zero optical path difference is identified as the singular point at which the phase becomes color invariant, and is determined accurately with a sub-sampling-interval resolution from the crossing point of the multi-color phase distributions obtained by the Fourier transform method. An experimental result is presented that demonstrates the performance of the phase-crossing algorithm. (c) 2005 Elsevier B.V. All rights reserved.
Scientific journal, English

Experimental study of coherence vortices: Local properties of phase singularities in a spatial coherence function
W Wang; ZH Duan; SG Hanson; Y Miyamoto; M Takeda
PHYSICAL REVIEW LETTERS, AMER PHYSICAL SOC, 96, 7, 073902, Feb. 2006, Peer-reviwed, By controlling the irradiance of an extended quasimonochromatic, spatially incoherent source, an optical field is generated that exhibits spatial coherence with phase singularities, called coherence vortices. A simple optical geometry for direct visualization of coherence vortices is proposed, and the local properties and the spatial evolution of coherence vortex are experimentally investigated. To our knowledge, this is the first direct and quantitative experimental measurement of a generic coherence vortex.
Scientific journal, English

EUVA's challenges toward 0.1nm accuracy in EUV at-wavelength interferometry
K Sugisaki; M Hasegawa; M Okada; YC Zhu; K Otaki; ZQ Liu; M Ishii; J Kawakami; K Murakami; J Saito; S Kato; C Ouchi; A Ohkubo; Y Sekine; T Hasegawa; A Suzuki; M Niibe; M Takeda
FRINGE 2005, SPRINGER-VERLAG BERLIN, 252-+, 2006, Peer-reviwed
International conference proceedings, English

Coherence holography: Holographic imaging with coherence function
Mitsuo Takeda; Wei Wang; Zhihui Duan; Yoko Miyamoto
HOLOGRAPHY 2005: INTERNATIONAL CONFERENCE ON HOLOGRAPHY, OPTICAL RECORDING, AND PROCESSING OF INFORMATION, SPIE-INT SOC OPTICAL ENGINEERING, 6252, 2006, Peer-reviwed, A technique of imaging with a spatial coherence function, referred to as coherence holography, is proposed. A hologram of a three-dimensional object is recorded with coherent light in the same manner as in conventional holography, but the hologram is illuminated with spatially incoherent light to reconstruct the object as the three-dimensional distribution of a spatial coherence function, rather than as the amplitude or the intensity distribution of the optical field. A simple optical geometry for direct visualization of the reconstructed coherence image is proposed, and the results of preliminary experiments of a computer-generated coherence hologram (CGCH) are presented, which demonstrate the potential of CGCH as a means for optical coherence tomography and profilometry.
International conference proceedings, English

Coherence holography: Principle and applications
Mitsuo Takeda; Wei Wang; Zhihui Duan; Yoko Miyamoto
SPECKLE06: SPECKLES, FROM GRAINS TO FLOWERS, SPIE-INT SOC OPTICAL ENGINEERING, 6341, 2006, Peer-reviwed, We review the principle and the applications of unconventional holography, called coherence holography(1,2), which we recently proposed as a general technique for the synthesis and the control of 3-D spatial coherence function. An object recorded in a hologram is reconstructed as the three-dimensional distribution of a complex spatial coherence function, rather than as the complex amplitude distribution of the optical field itself that usually represents the reconstructed image in conventional holography. We introduce a newly proposed simple optical geometry for the direct visualization of the reconstructed coherence image, along with the experimental results validating the proposed principle. We also show that coherence holography has potential applications in optical coherence tomography and profilometry(3) as well as in basic science of coherence vortices(4).
International conference proceedings, English

Experimental study of coherence vortices: Birth and evolution of phase singularities in the spatial coherence function
W Wang; ZH Duan; SG Hanson; Y Miyamoto; M Takeda
FRINGE 2005, SPRINGER-VERLAG BERLIN, 46-+, 2006, Peer-reviwed
International conference proceedings, English

Dispersion-free absolute interferometry based on angular spectrum scanning
ZH Duan; Y Miyamoto; M Takeda
OPTICS EXPRESS, OPTICAL SOC AMER, 14, 2, 655-663, Jan. 2006, Peer-reviwed, As an alternative to the conventional optical frequency scanning technique, an angular spectrum scanning technique is proposed for absolute interferometry. Instead of sweeping the optical frequency over a wide range of spectrum, we sweep the angular spectrum by changing the incident angle of a monochromatic plane wave with a spatial light modulator (SLM). The use of monochromatic light combined with the SLM enables dispersion-free absolute interferometry that is free from mechanical moving components. (c) 2006 Optical Society of America.
Scientific journal, English

Optical vortex metrology for nanometric speckle displacement measurement
W Wang; T Yokozeki; R Ishijima; A Wada; Y Miyamoto; M Takeda; SG Hanson
OPTICS EXPRESS, OPTICAL SOC AMER, 14, 1, 120-127, Jan. 2006, Peer-reviwed, As an alternative to correlation-based techniques widely used in conventional speckle metrology, we propose a new technique that makes use of phase singularities in the complex analytic signal of a speckle pattern as indicators of local speckle displacements. The complex analytic signal is generated by vortex filtering the speckle pattern. Experimental results are presented that demonstrate the validity and the performance of the proposed optical vortex metrology with nano-scale resolution. (c) 2006 Optical Society of America.
Scientific journal, English

EUV wavefront metrology at EUVA
Chidane Ouchi; Seima Kato; Masanobu Hasegawa; Takayuki Hasegawa; Hideo Yokota; Katsumi Sugisaki; Masashi Okada; Katsuhiko Murakami; Jun Saito; Masahito Niibe; Mitsuo Takeda
METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XX, PTS 1 AND 2, SPIE-INT SOC OPTICAL ENGINEERING, 6152, 104, 2006, Peer-reviwed, Precise measurements of the wavefront aberrations of projection optics with 0.1 nm RMS accuracy are indispensable to develop the extreme ultraviolet (EUV) lithography. In order to study measurement methods, we built the Experimental EUV Interferometer (EEI) that has built-in Schwarzschild-type optics as test optics and was supplied with EUV radiation of 13.5 nm in wavelength from a synchrotron radiation facility as a source light. The EEI can evaluate several methods of EUV interferometory replacing optical parts easily. Those methods are dividable into two categories, namely point diffraction interferometer (PDI) and lateral shearing interferometer (LSI) and those were experimentally compared. Finally, 0.045nm RMS of reproducibility was achieved with PDI method and the residual systematic error after removing specified errors was reduced to 0.064nm RMS excluding axial symmetrical aberrations. In addition, one of LSI-type methods also proved to have almost enough accuracy for the assembly of the projection optics.
International conference proceedings, English

Nanometric displacement measurement using phase singularities in Laguerre-Gauss transform of speckle pattern
Wei Wang; Tomoaki Yokozeki; Reika Ishijima; Steen G. Hanson; Mitsuo Takeda
INTERFEROMETRY XIII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 6292, 2006, Peer-reviwed, Contrary to the common belief of optical metrology, where the phase singularities are considered as obstacles in phase unwrapping, we propose a new technique that makes use of phase singularities in the complex signal representation of a speckle pattern as indicators of local speckle displacements. The complex signal representation is generated by Laguerre-Gauss filtering the dynamic speckle patterns. Experimental results are presented that demonstrate the validity and the performance of the proposed optical vortex metrology for lateral speckle displacement measurement with a large dynamic range.
International conference proceedings, English

Coherence current: contrast flow in coherence function
Wei Wang; Mitsuo Takeda
NATURE OF LIGHT: LIGHT IN NATURE, SPIE-INT SOC OPTICAL ENGINEERING, 6285, 2006, Peer-reviwed, Introducing scalar and vector densities for a mutual coherence function, we present a new conservation law for optical coherence of scalar wave fields in the form of continuity equation. This coherence conservation law provides new insights into topological phenomena for the complex coherence function. Some properties related to the newly introduced coherence vector density, such as a circulating coherence current associated with a coherence vortex, are investigated both theoretically and experimentally for the first time.
International conference proceedings, English

Absolute speckle interferometry with an angular-spectrum-tunable source
Zhihui Duan; Dong Wei; Akinori Yamada; Yoko Miyamoto; Mitsuo Takeda
SPECKLE06: SPECKLES, FROM GRAINS TO FLOWERS, SPIE-INT SOC OPTICAL ENGINEERING, 6341, (18-1)-(18-5), 2006, Peer-reviwed, Based on the fringe formation in the k-vector space, we proposed an angular spectrum scanning technique for absolute interferometry. Instead of sweeping the optical frequency over a wide range of spectrum, we tune the angular spectrum by changing the incident angle of a monochromatic plane wave with a spatial light modulator (SLM). In the experiment, we built an equivalent spatially incoherent "ring source" to realize the angular spectrum scanning, and applied an algorithm to compensate the offset fluctuation of the fringe intensity.
International conference proceedings, English

Sub-pixel speckle displacement measurement by using optical vortex metrology
Wei Wang; Tomoaki Yokozeki; Reika Ishijima; Atsushi Wada; Steen G. Hanson; Yoko Miyamoto; Mitsuo Takeda
SPECKLE06: SPECKLES, FROM GRAINS TO FLOWERS, SPIE-INT SOC OPTICAL ENGINEERING, 6341, (17-1)-(17-6), 2006, Peer-reviwed, As an alternative to correlation-based techniques widely used in conventional speckle metrology, we propose a new technique that makes use of phase singularities in the complex analytic signal of a speckle pattern as indicators of local speckle displacements. The complex analytic signal is generated by vortex filtering the speckle pattern. Experimental results are presented that demonstrate the validity and the performance of the proposed optical vortex metrology with nano-scale resolution.
International conference proceedings, English

Propagation analysis of the Laguerre-Gaussian beam with astigmatism
A Wada; T Ohtani; Y Miyamoto; M Takeda
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 22, 12, 2746-2755, Dec. 2005, Peer-reviwed, The entire range of transformations that a Laguerre-Gaussian (LG) beam with astigmatism can go through in free space is clarified. The transformations are governed by the relative phase between the astigmatic Hermite-Gaussian components. Formulas describing the behavior of this relative phase are obtained and used to classify and map the transformation patterns to initial beam parameters. The difference between an LG beam and a phase singular beam generated by a hologram under astigmatic conditions is also investigated. (c) 2005 Optical Society of America.
Scientific journal, English

Coherence holography
M Takeda; W Wang; ZH Duan; Y Miyamoto
OPTICS EXPRESS, OPTICAL SOC AMER, 13, 23, 9629-9635, Nov. 2005, Peer-reviwed, The principle of unconventional holography, called coherence holography, is proposed and experimentally demonstrated for the first time. An object recorded in a hologram is reconstructed as the three-dimensional distribution of a complex spatial coherence function, rather than as the complex amplitude distribution of the optical field itself that usually represents the reconstructed image in conventional holography. A simple optical geometry for the direct visualization of the reconstructed coherence image is proposed, along with the experimental results validating the proposed principle. Coherence holography is shown to be applicable to optical coherence tomography and profilometry. (c) 2005 Optical Society of America.
Scientific journal, English

Effect of comatic aberration on the propagation characteristics of laguerre - Gaussian beams
Atsushi Wada; Hiroyuki Ohminato; Takashi Yonemura; Yoko Miyamoto; Mitsuo Takeda
Optical Review, 12, 6, 451-455, Nov. 2005, Peer-reviwed, Seidel comatic aberration is an important cause of deformation for a Laguerre - Gaussian (LG) beam. In addition, mono-axial comatic aberration, whose phase modulation depends only on one transverse coordinate, is also an important cause of beam deformation. Deformation of an LG beam by such aberrations is analyzed through numerical simulation based on the angular spectrum method. It is also shown that for holographically generated LG beams quadratic spatial variation of grating pitch can produce seidel and mono-axial comatic aberrations. An example of an experimentally generated LG beam with mono-axial comatic aberration is reported. © 2005 The Optical Society of Japan.
Scientific journal, English

Common-path achromatic interferometer-coronagraph: nulling of polychromatic light
AV Tavrov; Y Kobayashi; Y Tanaka; T Shioda; Y Otani; T Kurokawa; M Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 30, 17, 2224-2226, Sep. 2005, Peer-reviwed, A three-dimensional common-path interferometer is proposed, which can achromatically null out an on-axis source while it maintains the detectability of an off-axis source. A geometric phase in the three-dimensional interferometer introduces an achromatic pi-phase shift to the light from the on-axis source, such that destructive interference nulls out the axial light at one of the ports of the interferometer. Light from the off-axis source, which is exempt from the pi-phase shift, comes out from both ports with equal intensity. The common-path scheme makes the system highly immune to environmental disturbances. (c) 2005 Optical Society of America.
Scientific journal, English

Pseudophase information from the complex analytic signal of speckle fields and its applications. Part I: Microdisplacement observation based on phase-only correlation in the signal domain
W Wang; N Ishii; SG Hanson; Y Miyamoto; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 44, 23, 4909-4915, Aug. 2005, Peer-reviwed, As an alternative to the intensity correlation used in conventional speckle metrology, we propose a new technique for displacement observation that is based on spatial-signal-domain phase-only correlation and that makes use of the pseudophase of the complex analytic signal generated from a Hilbert-filtered speckle pattern. Experimental results are presented that demonstrate the validity and the advantage of the proposed signal-domain phase-only correlation technique over both the conventional intensity correlation technique and the spatial-frequency-domain phase-only correlation technique. (c) 2005 Optical Society of America
Scientific journal, English

Pseudophase information from the complex analytic signal of speckle fields and its applications. Part II: Statistical properties of the analytic signal of a white-light speckle pattern applied to the microdisplacement measurement
W Wang; N Ishii; SG Hanson; Y Miyamoto; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 44, 23, 4916-4921, Aug. 2005, Peer-reviwed, To provide a theoretical background for the superiority of the signal-domain phase-only correlation (SDPOC) technique proposed here for microdisplacement measurement, we study the first- and the second-order statistical properties of the complex amplitude of an analytic signal of a white-light speckle pattern, under the assumption of a Gaussian random process, and give a formula for the autocorrelation function of the pseudophase associated with the complex analytic signal. Based on these results, we show mathematically that SDPOC has a performance advantage over conventional intensity-based correlation techniques. (c) 2005 Optical Society of America
Scientific journal, English

Beam deformation in holographic generation of Lagurerre Gaussian beam caused by hologram distortion
A. Wada; T. Yonemura; Y. Miyamoto; M. Takeda
International Symposium on Coherent Optical Science, PS11, Jul. 2005
International conference proceedings, English

A simple technique for the direct full-field observation of 3-D coherence function with a variable magnification
W. Wang; Z. Duan; Y. Miyamoto; Mitsuo Takeda
IQEC/CLEO-PR 2005, 1505-1506, Jul. 2005, Peer-reviwed
International conference proceedings, English

Verification of measurement basis in experiment of entanglement in orbital angular momentum of photons
D. Kawase; S. Takeuchi; K. Sasaki; A. Wada; Y. Miyamoto; M. Takeda
17th International Conference on Laser Spectroscopy (ICOLS 05), 153, Jun. 2005, Peer-reviwed
International conference proceedings, English

Experiments with the polychromatic light by means of geometric phase
A. Tavrov; T. Kurokawa; M. Takeda
CONO/LAT2005, LSM2, May 2005, Peer-reviwed
International conference proceedings, English

Phase singularities in analytic signal of white-light speckle pattern with application to micro-displacement measurement
W Wang; N Ishii; SG Hanson; Y Miyamoto; M Takeda
OPTICS COMMUNICATIONS, ELSEVIER SCIENCE BV, 248, 1-3, 59-68, Apr. 2005, Peer-reviwed, Rather than regarding the phase singularities as obstacles or nuisances in phase unwrapping, we explore new possibilities of making use of the phase singularities in optical metrology. Instead of intensity correlation techniques used in conventional speckle metrology, we propose a new technique of displacement measurement that makes use of the density of phase singularities in the complex analytic signal of the speckle pattern, which is generated by Hilbert filtering. Experimental results and theoretical analysis are presented that demonstrate the validity of the proposed technique. (c) 2004 Elsevier B.V. All rights reserved.
Scientific journal, English

プリズム角度と面形状の高精度測定：干渉角度計とその応用
葛宗濤; 齋藤隆行; 大井重徳; 武田光夫
光アライアンス, 日本工業出版, 16, 4, 49-51, Apr. 2005
Japanese

Experimental investigation of local properties and statistics of optical vortices in random wave fields
W Wang; SG Hanson; Y Miyamoto; M Takeda
PHYSICAL REVIEW LETTERS, AMER PHYSICAL SOC, 94, 10, 103902, Mar. 2005, Peer-reviwed, We present the first direct experimental evidence of the local properties of optical vortices in a random laser speckle field. We have observed the Berry anisotropy ellipse describing the anisotropic squeezing of phase lines close to vortex cores and quantitatively verified the Dennis angular momentum rule for its phase. Some statistics associated with vortices, such as density, anisotropy ellipse eccentricity, and its relation to zero crossings of real and imaginary parts of the random field, are also investigated by experiments.
Scientific journal, English

Optical frequency-domain reflectometry with a rapid wavelength-scanning superstructure-grating distributed Bragg reflector laser
Takuji Amano; Hideaki Hiro-Oka; Donghak Choi; Hiroyuki Furukawa; Fumiyoshi Kano; Mituo Takeda; Motoi Nakanishi; Kimiya Shimizu; Kohji Ohbayashi
Applied Optics, OSA - The Optical Society, 44, 5, 808-816, 10 Feb. 2005, Peer-reviwed, Superstructure-grating distributed Bragg reflector lasers are particularly suited for optical frequency-domain reflectometry optical-coherence tomography with wide wavelength tunability and frequency agility. We report theoretical estimates of and experimental results for the data acquisition speed, the observable depth range, the resolution, and the dynamic range of an optical frequency-domain reflectometry system that uses a superstructure-grating distributed Bragg reflector laser whose wavelength can be tuned from 1533 to 1574 nm with a tuning speed of 10 μs/0.1 nm step. © 2005 Optical Society of America.
Scientific journal, English

Optical frequency-domain reflectometry with a rapid wavelength-scanning superstructure-grating distributed Bragg reflector laser
T Amano; H Hiro-Oka; D Choi; H Furukawa; F Kano; M Takeda; M Nakanishi; K Shimizu; K Ohbayashi
APPLIED OPTICS, OPTICAL SOC AMER, 44, 5, 808-816, Feb. 2005, Peer-reviwed, Superstructure-grating distributed Bragg reflector lasers are particularly suited for optical frequency-domain reflectometry optical-coherence tomography with wide wavelength tunability and frequency agility. We report theoretical estimates of and experimental results for the data acquisition speed, the observable depth range, the resolution, and the dynamic range of an optical frequency-domain reflectometry system that uses a superstructure-grating distributed Bragg reflector laser whose wavelength can be tuned from 1533 to 1574 nm with a tuning speed of 10 mus/0.1-nm step. (C) 2005 Optical Society of America.
Scientific journal, English

Second-order statistical property of partially developed speckle and its applications to speckle metrology
W Wang; SG Hanson; Y Miyamoto; M Takeda
2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, IEEE, 840-841, 2005, Peer-reviwed, Some second-order statistics for partially developed speckle have been investigated and analytical expressions for the cross-correlation function have been derived. Experiment results are provided to demonstrate the validity of the proposed theorem.
International conference proceedings, English

A simple technique for the direct full-field observation of 3-D coherence function with variable scale control
W Wang; ZH Duan; Y Miyamoto; M Takeda
2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, IEEE, 898-899, 2005, Peer-reviwed, A simple technique for the direct full field observation of 3-D spatial coherence function with the capability of variable scale adjustment is proposed. Experimental results are presented to demonstrate the validity of the proposed method.
International conference proceedings, English

A novel interferometer for measuring the wavefront of multi-wavelength optical pickups
ZT Ge; T Saitou; M Kurose; M Takeda
2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, IEEE, 1012-1013, 2005, Peer-reviwed, A novel wavefront measurement interferometer is developed that enables the user to evaluate the wavefront of multi-wavelength optical pickups. The interferometer is designed to operate at wavelengths of 405nm, 650nm and 780nm and over the NA range of from 0.6 to 0.85. The instrument is equal path that enables the user to measure pickups with very short coherence length. System accuracy is evaluated and a good agreement with Fujinon V10 interferometer is achieved. Furthermore, the point spread function calculated from the obtained wavefront is compared with the measured spot intensity distribution and the results correlate well with each other.
International conference proceedings, English

Phase-crossing algorithm for white-light fringe analysis
ME Pawlowski; Y Sakano; Y Miyamoto; M Takeda
2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, IEEE, 1010-1011, 2005, Peer-reviwed, A spectral phase-crossing algorithm for the analysis of white-light fringes obtained by use of a color-insensitive camera is presented. The technique searches for the zero group-velocity optical path difference (OPD) position from a crossing point of two phases of spectrally resolved fringes, which are obtained from the Fourier spectra of white-light interferograms.
International conference proceedings, English

LCD-based low spatial coherence interferometer
Z Duan; P Pavlicek; Y Miyamoto; M Takeda
Holography, Diffractive Optics, and Applications II, Pts 1 and 2, SPIE-INT SOC OPTICAL ENGINEERING, 5636, 34-39, 2005, Peer-reviwed, An interferometer based on the spatial coherence detection has been developed for absolute height measurement. The location of a coherence peak resulting from the illumination of an extended quasi-monochromatic spatially incoherent light source with zone-plate-like spatial structure gives the longitudinal depth information. Besides simplifying the control of the light source structure, LCD-SLM eliminates the mechanical movement. Experiments of step height detection and profilometry of an object with a rough surface are presented that demonstrate the validity of the principle.
International conference proceedings, English

Profile measurement of objects with discontinuous surfaces by modified temporal phase unwrapping
A Tian; T Makihata; M Takeda; ZD Jiang
Advanced Materials and Devices for Sensing and Imaging II, SPIE-INT SOC OPTICAL ENGINEERING, 5633, 23-30, 2005, Peer-reviwed, A profile measurement technique for objects with spatially isolated surfaces is presented. The technique is based on the Fourier fringe analysis combined with temporal phase unwrapping. A sequence of sinusoidal fringe patterns with a varying pitch is projected onto objects, and the temporal variation of the fringe signal is recorded with a CCD camera. The phase of the temporal fringe signal is detected at each pixel by the Fourier transform method, and is temporally phase unwrapped, independently from other pixels. The temporal frequency of the fringe signal estimated from the time slope of the unwrapped phase provides the information about the absolute surface heights of the objects. It will be shown that, because of its filtering function that can exclude higher order harmonics, the Fourier transform method is more robust to the nonlinear characteristics of a LCD projector and a CCD image sensor, than the phase shift technique that assumes a pure sinusoidal fringe signal. The measurement of objects with large discontinuities and/or spatially isolated surfaces is demonstrated by experiment.
International conference proceedings, English

Multi-spectral phase-crossing white-light interferometry
M Pawlowski; Y Sakano; Y Miyamoto; M Takeda
Eighth International Symposium on Laser Metrology, SPIE-INT SOC OPTICAL ENGINEERING, 5776, 88-93, 2005, Peer-reviwed, A new method of white-light fringes analysis called multi-spectral phase-crossing detection is presented. The technique is based on analysis of phase distributions of at least two white-light interferograms recorded simultaneously by detectors with mutually different spectral sensitivities. The analysis of the phase crossing of multiple white-light interferograms with different spectral bands gives us the possibility to find the position of zero optical path difference without ambiguity. The theoretical background and measurement results are presented.
International conference proceedings, English

Comparison of EUV interferometry methods in EUVA project
S Kato; C Ouchi; M Hasegawa; A Suzuki; T Hasegawa; K Sugisaki; M Okada; Z Yucong; K Murakami; J Saito; M Niibe; M Takeda
Emerging Lithographic Technologies IX, Pts 1 and 2, SPIE-INT SOC OPTICAL ENGINEERING, 5751, 110-117, 2005, Peer-reviwed, We are developing an at-wavelength interferometer for EUV lithography systems. The goal is the measurement of the wavefront aberration for a six-aspherical mirror projection optic. Among the six methods that EEI can measure, we selected CGLSI and PDI for comparison. PDI is a method well-known for its high accuracy, while CGLSI is a simple measurement method. Our comparison of PDI and CGLSI methods, verified the precision of the CGLSI method. The results show a difference between the methods of 0.33nm RMS for terms Z5-36. CGLSI measurement wavefronts agree well with PDI for terms Z5-36, and it is thought of as a promising method. Using FFT analysis, we estimated and then removed the impact of flare on the wavefront. As a result of having removed the influence of flare, the difference between CGLSI and PDI improved to only 0.26nm RMS in Zernike 5-36 terms. We executed PDI wavefront retrieval with FFT, which has not been used till now. By confirming that the difference between methods using FFT and Phase shift is 0.035nm RMS for terms Z5-36, we have proven that PDI wavefront analysis with FFT is possible.
International conference proceedings, English

Phase distribution measurements of Laguerre-Gaussian beam with Fourier transform fringe analysis and polarization methods
Yoko Miyamoto; Takashi Yonemura; Atsushi Wada; Hiroyuki Ohminato; Mitsuo Takeda
Conference on Lasers and Electro-Optics Europe - Technical Digest, p.78, CH-10-TUE, 2005, Peer-reviwed, The Laguerre Gaussian (LG) beam is an optical beam with doughnut-shaped intensity distribution and a phase singularity on the beam axis. In applications of LG beams such as particle trapping and rot
ational manipulation, beam quality is an important issue. Computer holograms that generate LG beams from Gaussian inputs are also used to analyze orbital angular momentum photon states by reversing the input and output. In such a situation, a hologram which produces a less than ideal LG beam from an ideal Gaussian beam will convert a less than ideal LG beam back to an ideal Gaussian beam, limiting the precision of the entire analysis. Detailed evaluation of intensity and especially phase distributions of generated LG beams are important for both types of applications. In this paper we compare two methods for the measurement of phase distribution of LG beams. The first method is interference fringe analysis by Fourier transform[1]. This method deliberately introduces a tilt between the measured LG beam and reference beam, creating fine interference fringes with a roughly constant pitch across the measurement plane. The phase distribution is extracted from the spatial modulation to these carrier fringes using Fouirier transform and filtering. This method has been used in most of our previous works. Fig. 1 is the measurement result for a charge 1 phase singular beam. The method requires a single image and is robust against noise and nonlinearities. Spatial resolution is limited due to the filtering, although interpolation is possible. The second method combines polarization and interference, and was first proposed by Harvey et al. The LG beam and referernce are prepared in muitually orthogonal polarizations and phase distribution is obtained from the polarization analysis of the synthesized beam. Fig. 2 is the measurement result for the same beam as Fig. 1. This method allows determination of phase pixel by pixel. The downside is that complete reconstruction of the Stokes parameters requires four images, and stability of the interferometer during these four measurements is crucial. Typical artifact caused by interferometer instability is discussed. © 2005 IEEE.
International conference proceedings, English

Deformation due to distorted hologram for generation of Laguerre Gaussian beam
Atsushi Wada; Hiroyuki Ohminato; Takashi Yonemura; Yoko Miyamoto; Mitsuo Takeda
Conference on Lasers and Electro-Optics Europe - Technical Digest, p.100 (CC-11-WED), 2005, Peer-reviwed
International conference proceedings, English

Experimental study of local properties of optical vortices in random isotropic field
Wang Wei; Steen G. Hanson; Yoko Miyamoto; Mitsuo Takeda
Conference on Lasers and Electro-Optics Europe - Technical Digest, p.124 (CH1-4-THU), 2005, Peer-reviwed
International conference proceedings, English

Spatial coherence interferometry using a sinusoidal spatial-frequency comb
Zhihui Duan; Pavel Pavelicek; Yoko Miyamoto; Mitsuo Takeda
Conference on Lasers and Electro-Optics Europe - Technical Digest, p.140 (CH4-1-FRI), 2005, Peer-reviwed
International conference proceedings, English

Second-order statistical property of partially developed speckle and its applications to speckle metrology
Wang Wei; Steen G. Hanson; Yoko Miyamoto; Mitsuo Takeda
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest, 2005, 1423-1424, 2005, Peer-reviwed, Some second-order statistics for partially developed speckle have been investigated and analytical expressions for the cross-correlation function have been derived. Experiment results are provided to demonstrate the validity of the proposed theorem.
International conference proceedings, English

Phase-crossing algorithm for white-light fringe analysis
Michal E. Pawlowski; Youhei Sakano; Yoko Miyamoto; Mitsuo Takeda
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest, 2005, 1691-1692, 2005, Peer-reviwed, A spectral phase-crossing algorithm for the analysis of white-light fringes obtained by use of a color-insensitive camera is presented. The technique searches for the zero group-velocity optical path difference (OPD) position from a crossing point of two phases of spectrally resolved fringes, which are obtained from the Fourier spectra of white-light interferograms.
International conference proceedings, English

A novel interferometer for measuring the wavefront of multi-wavelength optical pickups
Zongtao Ge; Takayuki Saitou; Minoru Kurose; Mitsuo Takeda
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest, 2005, 1693-1694, 2005, Peer-reviwed, A novel wavefront measurement interferometer is developed that enables the user to evaluate the wavefront of multi-wavelength optical pickups. The interferometer is designed to operate at wavelengths of 405nm, 650nm and 780nm and over the NA range of from 0.6 to 0.85. The instrument is equal path that enables the user to measure pickups with very short coherence length. System accuracy is evaluated and a good agreement with Fujinon V10 interferometer is achieved. Furthermore, the point spread function calculated from the obtained wavefront is compared with the measured spot intensity distribution and the results correlate well with each other.
International conference proceedings, English

3D common-path interferometer: Achromatic nulling of on-axial light
Alexander V. Tavrov; Yukitoshi Otani; Takashi Kurokawa; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, 5905, 1-7, 2005, Peer-reviwed, Three-dimensional common-path interferometer is proposed to obtain achromatic nulling for the on-axial source
the off-axial source remains detectable. The 3D interferometer involves ±90° polarization rotations in each interferometer arm. That results in the achromatic 180° phase shift, so that the on-axial source interferes destructively. Depending on the source axial position, the light energy is split by different ratios between the Bright and the Nulled interferometers outputs. For the linearly polarized on-axial source, all the energy at nearly 100% is directed to the Bright port. For the off-axial source, the light is split by the ratio at nearly 50% / 50 % between the Bright and the Nulled ports. The common-path scheme compensates effectively the optical path difference (OPD) and it remains stable to mechanical vibrations. Theory, simulations and preliminary breadboard experiments are shown to be in reasonable agreement.
International conference proceedings, English

Synthesis and spatial evolution of longitudinal coherence vortex
Wei Wang; Zhihui Duan; Steen G. Hanson; Yoko Miyamoto; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, 5924, 1-7, 2005, Peer-reviwed, By controlling the irradiance of an extended quasi-monochromatic, spatially incoherent source with a spatial light modulator, we generated a special optical field that exhibits a high degree of coherence with phase singularities for a specific pair of points at specified locations along the axis of beam propagation. Some local properties associated with coherence vortices, such as the Berry anisotropy ellipse describing the anisotropic degree of coherence close to a vortex core and the Dennis angular momentum rule for its associated phase, are also investigated experimentally.
International conference proceedings, English

Comparisons between EUV at-wavelength metrological methods
Katsumi Sugisaki; Masashi Okada; Yucong Zhu; Katsura Otaki; Zhiqiang Liu; Jun Kawakami; Mikihiko Ishii; Jun Saito; Katsuhiko Murakami; Masanobu Hasegawa; Chidane Ouchi; Seima Kato; Takayuki Hasegawa; Akiyoshi Suzuki; Hideo Yokota; Masahito Niibe; Mitsuo Takeda
Proceedings of SPIE - The International Society for Optical Engineering, 5921, 1-8, 2005, Peer-reviwed, Comparisons between several at-wavelength metrological methods are reported. The comparisons are performed by measuring one test optic with several kinds of measurement methods from the viewpoints of accuracy, precision and practicality. According to our investigation, we found that the PDI, the LDI, and the CGLSI are the most suitable methods for evaluating optics for EUV lithography.
International conference proceedings, English

Phase distribution measurements of phase-singular beam with Fourier transform fringe analysis and polarization methods
Y. Miyamoto; T. Yonemura; A. Wada; H. Ohminato; M. Takeda
17th International Conference on Laser Spectroscopy (ICOLS 05), p. 181, 2005, Peer-reviwed
International conference proceedings, English

Effect of hologram distortion on detection and generation of orbital angular momentum modes
A. Wada; H. Ohminato; T. Yonemura; Y. Miyamoto; M. Takeda
IQEC, International Quantum Electronics Conference Proceedings, 2005, 1317-1318, 2005, Peer-reviwed, Profile of Laguerre Gaussian modes detected by holographic mode detector can be deformed into triangular shape due to hologram distortion. This deformation can generally appear for all holograms fabricated by a raster scan based system.
International conference proceedings, English

Verification of hologram position in experiment of entanglement in orbital angular momentum of photons
Daisuke Kawase; Atsushi Wada; Shigeki Takeuchi; Yoko Miyamoto; Keiji Sasaki; Mitsuo Takeda
IQEC, International Quantum Electronics Conference Proceedings, 2005, 1319-1320, 2005, Peer-reviwed, Experiments of entanglement in orbital angular momentum, hologram (with a dislocation point) are used to convert orbital angular momentum, making basis identification difficult. In our analysis, we have succeeded in identifying measurement basis.
International conference proceedings, English

Achromatic pi-phase shift for nano-sensing interferometry: Nulling of polychromatic on-axial light, off-axial light detection
A Tavrov; T Kurokawa; M Takeda
2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, IEEE, 895-897, 2005, Peer-reviwed, Achromatic 180 degrees-phase shift is demonstrated to null the polychromatic light emitted from on axial direction in order to detect the light emitted from off-axial source. Nulling of the polychromatic light over 300 nm bandwidth is shown by simple experiment.
International conference proceedings, English

A novel profilometry using frequency comb light source
S Choi; M Yamamoto; D Moteki; T Shioda; Y Tanaka; M Takeda; T Kurokawa
2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, IEEE, 1007-1009, 2005, Peer-reviwed, A novel profilometry using a frequency comb light source is proposed. This method realizes step height measurement without mechanical scanning. We have confirmed the system with high accuracy with this method.
International conference proceedings, English

Application of cross-grating interferometry for EUV wavefront measurement
S. Kato; C. Ouchi; M. Hasegawa; A. Ohkubo; Y. Sekine; A. Suzuki; T. Hasegawa; Y. Tanaka; K. Murakami; J. Saito; M. Ishii; J. Kawakami; K. Sugisaki; M. Okada; Y. Zhu; K. Otaki; Z. Q. Liu; M. Niibe; M. Takeda
3rd International Extreme Ultraviolet Lithography Symposium, Technical Digest, MeP15, Nov. 2004, Peer-reviwed
International conference proceedings, English

Propagation analysis of Laguerre-Gaussian beam with astigmatism
A. Wada; H. Ohminato; T. Yonemura; Y. Miyamoto; M. Takeda
ICO International Conference, Optics and Photonics in Technology Frontier, Technical Digest, 63-64, Jul. 2004, Peer-reviwed
International conference proceedings, English

Density of phase singularities in analytic signal of speckle pattern with application to micro-displacement measurement
W. Wang; N. Ishii; S. G. Hanson; Y. Miyamoto; M. Takeda
ICO International Conference, Optics and Photonics in Technology Frontier, Technical Digest, 407-408, Jul. 2004
International conference proceedings, English

Pseudo-phase information of complex analytic signal of speckle fields and its applications: micro-displacement measurement based on phase-only correlation in signal domain
W Wang; N Ishii; Y Miyamoto; M Takeda
OPTICAL METROLOGY IN PRODUCTION ENGINEERING, SPIE-INT SOC OPTICAL ENGINEERING, 5457, 44-49, 2004, Peer-reviwed, As an alternative to the intensity correlation technique used in conventional speckle metrology, we propose a new technique of displacement measurement based on spatial signal-domain phase-only correlation that makes use of the pseudo phase of the complex analytic signal generated from a Hilbert-filtered speckle pattern. Experimental results are presented that demonstrate the validity and the advantage of the proposed signal-domain phase-only correlation technique over the conventional intensity correlation technique.
International conference proceedings, English

Achromatic coronagraph based on out-of-plane common-path nulling interferometer
AV Tavrov; Y Tanaka; T Shioda; T Kurokawa; M Takeda
NEW FRONTIERS IN STELLAR INTERFEROMETRY, PTS 1-3, SPIE-INT SOC OPTICAL ENGINEERING, 5491, 824-830, 2004, Peer-reviwed, 3D common-path interferometer is proposed to obtain achromatic nulling for star coronagraphy. Common-path scheme compensates optical path difference (OPD) effectively and is stable to mechanical vibrations. 3D ray geometry involves polarization rotations +/-90degrees in each interferometer arm and results in achromatic 180degrees phase shift for destructive interference for on-axial source. The interferometer throughput is obtained at nearly 100% for entire polarized light and nearly 50/50 ratio of light energy is split between Bright and Nulled ports for off-axial source. Theory, simulations and preliminary breadboard experiments are shown in reasonable agreement.
International conference proceedings, English

Spatio-spectral digital holography for full-field tomographic imaging with adaptive focusing
M Pawlowski; Y Sakano; Y Miyamoto; M Takeda; K Obayashi
INTERFEROMETRY XII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 5531, 121-126, 2004, Peer-reviwed, A new technique, called spatio-spectral digital holography, is proposed. The technique is based on the combination of the principles of a spectral interference microscope and digital holography, where the spectral interferometry provides the function of full-field tomographic imaging, and digital holography gives a microscope objective the function of adaptive numerical focusing. Experimental results are presented that demonstrate the validity of the proposed principle.
International conference proceedings, English

Statistical property of the complex analytic signal of white-light speckle pattern applied to micro-displacement measurement
W Wang; N Ishii; Y Miyamoto; M Takeda
INTERFEROMETRY XII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 5531, 146-152, 2004, Peer-reviwed, Under the assumption of Gaussian random process, we discuss the first and the second order statistical properties of the complex amplitude of analytic signal of the white-light speckle pattern. We derive the autocorrelation function of the pseudo phase. Based on these results, we show mathematically that the proposed signal domain phase-only correlation (SD-POC) has advantage over the conventional intensity-based correlation techniques in its performance of micro-displacement measurement. We also present experimental results that support the theory.
International conference proceedings, English

Double-source interferometry for reducing spurious noise fringes
ZQ Liu; T Gemma; S Udagawa; M Takeda
INTERFEROMETRY XII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 5531, 193-202, 2004, Peer-reviwed, A new technique of double-source interferometry is proposed, which can suppress spurious noise fringes arising from the interference with unwanted lights reflected from a surface that is not under test. Two collimated beams from a pair of mutually incoherent monochromatic sources are introduced into an interferometer to generate two sets of interference fringes, each of which is a superposition of signal fringes and noise fringes. The key idea is to choose the angle between the two beams in such a manner that the noise fringes generated by one beam become 180 degree out of phase from those generated by the other beam; thereby the noise fringes are canceled out while the signal fringes are maintained. The technique is also suited to the measurement of an optical parallel plate where noise fringes are unavoidable because of reflection from the rear surface. Experimental results are presented that demonstrate the validity of the proposed principle.
International conference proceedings, English

An improved illumination system for spatial coherence control
ZQ Liu; T Gemma; J Rosen; M Takeda
INTERFEROMETRY XII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 5531, 220-227, 2004, Peer-reviwed, A longitude coherence control system needs a source that is temporally coherent and yet spatially incoherent. For this reason, a zone plate-like pattern is imaged onto a rotating ground glass. Generally the ground glass exhibits a strong directivity. It is far from an ideal uniform diffuser that is implicitly assumed in the theory. To solve this problem, we propose a new illumination system. In our system, the beam illuminating the zone plate-like pattern is focused on the test surface. We measured the longitudinal coherence functions in our optical system. The result shows that the longitude coherent function is better controlled in our interferometer.
International conference proceedings, English

Synthetic spatial coherence function for optical tomography and profilometry: influence of the observation condition
Z Duan; H Kozaki; Y Miyamoto; J Rosen; M Takeda
INTERFEROMETRY XII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 5531, 236-243, 2004, Peer-reviwed, We address the basic issue of the observation condition in a synthetic coherence function applied to optical tomography and profilometry, which has not been made clear in previous papers. We present a more general theory for interference fringe formation for spatial coherence control with a synthetic source. The generalized theory predicts the existence of the observation condition that can make the measurement insensitive to the tilt of the object, which will open the new possibility of measuring objects with rough surfaces. We present experimental results that quantitatively verify the validity of the principle and the prediction.
International conference proceedings, English

OFDR with an SSG-DBR laser
T Amano; H Hiro-Oka; DH Choi; H Furukawa; F Kano; M Takeda; M Nakanishi; K Shimizu; K Ohbayashi
INTERFEROMETRY XII: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 5531, 375-382, 2004, Peer-reviwed, Recently, frequency-domain (FD)-optical-coherence-tomography (OCT) methods have been investigated extensively as more efficient and sensitive system compared with conventional time-domain (TD)-OCT. Superstructure-grating-distributed-Bragg-reflector (SSG-DBR) lasers are particularly suited for optical frequency domain reflectometry (OFDR)-OCT with its wide wavelength tunability and frequency agility. We have made a discrete frequency OFDR-OCT system with an SSG-DBR laser, which can tune the wavelength from 1533 to 1574 nm with tuning speed of 10 mus per 0.1 nm step. The theoretical expression of the discrete frequency OFDR-OCT is given. Utilizing near-transparent nature of enamel of teeth in the wavelength region of the SSG-DBR laser and long object range of the OFDR-OCT, we have carried out OCT measurements on teeth. Experimental OCT imaging of a canine are reported here.
International conference proceedings, English

Recent progress of EUV wavefront metrology in EUVA
M Hasegawa; C Ouchi; T Hasegawa; S Kato; A Ohkubo; A Suzuki; K Sugisaki; M Okada; K Otaki; K Murakami; J Saito; M Niibe; M Takeda
ADVANCES IN MIRROR TECHNOLOGY FOR X-RAY, EUV LITHOGRAPHY, LASER, AND OTHER APPLICATIONS II, SPIE-INT SOC OPTICAL ENGINEERING, 5533, 27-36, 2004, The recent experimental results of EUV wavefront metrology in EUVA are reported. EUV Experimental Interferometer (EEI) was built at the NewSUBARU synchrotron facility of University of Hyogo to develop the most suitable wavefront measuring method for EUV projection optics. The result is to be reflected on EWMS (EUV Wavefront Metrology System) that measures wavefront aberrations of a six-aspherical mirror projection optics of NA0.25, of a mass-production EUV lithography tool. The experimental results of Point Diffraction Interferometer (PDI) and Lateral Shearing Interferometer (LSI) are shown and the error factors and the sensitivity of astigmatism measurements of these methods are discussed. Furthermore, for reducing these kinds of errors, another type of shearing interferometer called DTI (Digital Talbot interferometer) is newly introduced.
International conference proceedings, English

High-resolution two-dimensional angle measurement technique based on fringe analysis
ZT Ge; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 42, 34, 6859-6868, Dec. 2003, Peer-reviwed, A novel angle-measurement technique based on fringe analysis for phase-measuring profilometry is proposed. A two-dimensional (2-D) angle between two mirror surfaces is determined by least-squares fitting of a plane to the 2-D distribution of the phase difference introduced by the 2-D tilt angle. To evaluate the performance of the proposed technique, numerical simulations that use the Fourier-transform technique and the phase-shift technique for fringe analysis were performed, and the results are compared. A 2-D angle-measurement interferometer based on a Mirau interference microscope was developed that demonstrated the validity of the proposed principle. It is shown by simulation and experiment that the proposed 2-D angle-measurement technique can achieve both a wide measurement range and a high angular resolution simultaneously. (C) 2003 Optical Society of America.
Scientific journal, English

Fourier transform spectral interferometric micro-profilometry for large step-height measurement with improved signal processing
D. S. Mehta; H. Hinosugi; S. Saito; M. Takeda; T. Kurokawa; H. Takahashi; M. Ando; M. Shishido; T. Yoshizawa
Proceedings of International Conference on Laser Applications and Optical Metrology, 586-591, Dec. 2003, Peer-reviwed
International conference proceedings, English

Three-dimensional sensing for shape recognition
D. Choudhury; M. Takeda
Proceedings of International Conference on Laser Applications and Optical Metrology, 280-284, Dec. 2003, Peer-reviwed
International conference proceedings, English

Conservation of orbital angular momentum in phase singular beams with astigmatism
Yoko Miyamoto; Atsushi Wada; Hiroyuki Ohminato; Mitsuo Takeda
16th International Conference on Laser Spectroscopy (ICOLS 03), 199, Jul. 2003, Peer-reviwed
International conference proceedings, English

Spatial coherence radar applied for tilted surface profilometry
M Gokhler; ZH Duan; J Rosen; M Takeda
OPTICAL ENGINEERING, SPIE-INT SOCIETY OPTICAL ENGINEERING, 42, 3, 830-836, Mar. 2003, Peer-reviwed, A new method of spatial coherence profilometry is demonstrated. The surface profile is measured by shifting the spatial degree of coherence gradually in its own space of existence, and modulating its phase angle. In each point of the sample we analyze the change of light intensity versus the phase of a Fresnel zone pattern used as the intensity distribution of an incoherent quasi monochromatic source. The tilt of the surface is measured by gradually shifting the Fresnel zone plate on its transverse plane. This shift of the light source rotates the spatial degree of coherence around the coordinate origin until the condition of maximum interference visibility is fulfilled. The method works without any mechanical movement and a quasimonochromatic light illuminates the interferometric system. Experimental demonstration of the new method is presented. (C) 2003 Society of Photo-Optical Instrumentation Engineers.
Scientific journal, English

Spectral interference Mirau microscope with an acousto-optic tunable filter for three-dimensional surface profilometry
DS Mehta; S Saito; H Hinosugi; M Takeda; T Kurokawa
APPLIED OPTICS, OPTICAL SOC AMER, 42, 7, 1296-1305, Mar. 2003, Peer-reviwed, A nonmechanical scanning Mirau-type spectral interference microscope has been developed for the measurement of three-dimensional surface profiles of discontinuous objects. An acousto-optic tunable filter (AOTF) is used as a high-resolution spectral filter, which scans the optical frequency of the broadband light emitted from a superluminescent diode. To generate spectral fringes that make full use of the limited coherence length of the filtered light we unbalanced the Mirau interferometric system by positioning the reference mirror nearly halfway between the top and the bottom of the step height. When the frequency of the broadband light source is scanned by an AOTF, the interference fringes move in opposite directions on the top and the bottom of the object. To uniquely determine the sign of the fringe movement over the large area of the object, we developed a three-dimensional Fourier-transform technique, and from the detected sign of the fringe movement and phase information, we determined the three-dimensional step height. Experimental results of the measurement of 100-mum step height are presented. The main advantages of the proposed system are that it provides nonmechanical scanning and a large measurement range without ambiguity in the sign of the phase. (C) 2003 Optical Society of America.
Scientific journal, English

Profilometry based on two-photon absorption in a silicon avalanche photodiode
Y Tanaka; N Sako; T Kurokawa; H Tsuda; M Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 28, 6, 402-404, Mar. 2003, Peer-reviwed, A novel profilometry method based on two-photon absorption in a silicon avalanche photodiode is proposed. This method has a wide dynamic range, from millimeters to tens of meters. The principle is experimentally confirmed with a fiber-optic Mach-Zehnder interferometer. (C) 2003 Optical Society of America.
Scientific journal, English

Spectral interferometric microscope with tandem liquid-crystal Fabry-Perot interferometers for extension of the dynamic range in three-dimensional step-height measurement
DS Mehta; H Hinosugi; S Saito; M Takeda; T Kurokawa; H Takahashi; M Ando; M Shishido; T Yoshizawa
APPLIED OPTICS, OPTICAL SOC AMER, 42, 4, 682-690, Feb. 2003, Peer-reviwed, The maximum measurable range of a spectral interference microscope depends on the coherence length of the light transmitted by its tunable spectral filter. To achieve a large range in step-height measurement we have developed a new tunable spectral filter that uses tandem liquid-crystal Fabry-Perot interferometers (LC-FPIs), which can simultaneously attain both a high spectral resolution and a large tuning range. Fringe visibility measurements were carried out, and it was found that the coherence length of the light transmitted through tandem LC-FPIs is two times larger than that transmitted through a single LC-FPI. Using this novel tunable spectral filter, we developed a new spectral interference microscope for the measurement of three-dimensional shapes of discontinuous objects. Experimental results of step-height measurements both with a single LC-FPI and with tandem LC-FPIs are presented for a combination of standard steel gauge block sets with 1-, 99-, and 100-mum steps. A large range (1-100 mum) of measurement with submicrometer resolution was achieved with tandem LC-FPIs that was not possible with our previous system in which a single LC-FPI was used. (C) 2003 Optical Society of America.
Scientific journal, English

Three-dimensional target recognition using the phase information from a Fourier transform profilometer
D Choudhury; M Takeda
OPTICAL INFORMATION SYSTEMS, SPIE-INT SOC OPTICAL ENGINEERING, 5202, 168-175, 2003, Peer-reviwed, We propose a new technique for three-dimensional (3D) target recognition using the phase information from a Fourier transform profilometer. Instead of cross-correlating the 3D target/nontargets induced distorted grating patterns or the associated phase differences directly, the phase information are rather utilized to synthesize two complex harmonic functions, spatial frequency distributions of which are proportional to the computed profilometric phase maps of the target and the nontargets and hence to respective shape information. These complex harmonic functions due to the target and the nontargets are cross-correlated to produce highest correlation peak at the target location and almost no correlation peak for others. The feasibility of the technique is demonstrated by simulation and experiments showing an excellent discrimination capability for 3D target recognition.
International conference proceedings, English

Transformation of orbital angular momentum photon states under astigmatism
Y. Miyamoto; A. Wada; T. Ohtani; N. Nishihara; M. Takeda
The 8th International Symposium on Advanced Physical Fields: Advanced Materials for Quantum Computing (APF8), 46, Jan. 2003, Peer-reviwed
International conference proceedings, English

Phase singularities in dynamic speckle fields and their applications to optical metrology
W Wang; N Ishii; Y Miyamoto; M Takeda
SPECKLE METROLOGY 2003, PROCEEDINGS, SPIE-INT SOC OPTICAL ENGINEERING, 4933, 175-180, 2003, Peer-reviwed, Instead of the intensity information used in conventional speckle metrology, we explore new possibilities of making use of the phase information of speckle patterns. We propose a new technique of displacement measurement that makes use of the phase singularities in the analytic signal of the speckle pattern, which is generated by Hilbert filtering. Experimental results are presented that demonstrate the validity and the limitation of the proposed technique.
International conference proceedings, English

Reconstruction of phase-shift digital holograms with unknown phase-shift by Fourier fringe analysis
A Wada; T Kurashima; Y Miyamoto; M Takeda
OPTICAL MEASUREMENT SYSTEMS FOR INDUSTRIAL INSPECTION III, SPIE-INT SOC OPTICAL ENGINEERING, 5144, 138-141, 2003, Peer-reviwed, A new technique is proposed that enables reconstruction of phase-shift digital holograms with unknown phase shifts. The technique is based on the phase-shift technique combined with the Fourier transform technique to have the advantages of these two techniques. First the unknown phase shifts are determined by the Fourier transform technique, and then the complex field recorded in the digital hologram is obtained by the phase shift technique using the knowledge of the phase shifts. Experimental results are presented that demonstrate the validity of the principle.
International conference proceedings, English

Achromatic nulling interferometer based on a geometric spin-redirection phase
A Tavrov; R Bohr; M Totzeck; H Tiziani; M Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 27, 23, 2070-2072, Dec. 2002, Peer-reviwed, Nulling interferometry aims to perform destructive interference achromatically. It is used to detect a faint source near a bright one and to provide dark field, an annular pupil, and rotational shear. A nulling out-of-plane interferometer that utilizes the geometric phase of spin redirection is proposed. The degree of nulling is determined by beam collimation. and angular orientation of mirrors. Simulations and experiments are in reasonable agreement. (C) 2002 Optical Society of America.
Scientific journal, English

Three-dimensional target recognition by profilometric phase coding
D. Choudhury; M. Takeda
Optics and Photonics News (OSA), 13, 12, 47, Dec. 2002, Peer-reviwed
Scientific journal, English

Holographic generation of Laguerre-Gaussian beam with astigmatic illumination beam
A. Wada; Y. Miyamoto; T. Ohtani; N. Nishihara; M. Takeda
Proc. 3rd International Conference on Optics-photonics Design and Fabrication, ODF2002, 123-124, Nov. 2002, Peer-reviwed
International conference proceedings, English

Spatial coherence optical tomography and profilometry: A new principle for dispersion-free measurement
Z.-H. Duan; M. Gokhler; J. Rosen; H. Kozaki; N. Ishii; M. Takeda
Proceedings of Asian Symposium on Biomedical Optics and Photomedicine, BOPM2002, 138-139, Oct. 2002, Peer-reviwed
International conference proceedings, English

Absolute 3-D sensor with single fringe-pattern recording
Y. Kasai; Y. Miyamoto; M. Takeda; H. Tanaka; R. Gu
Proc. SPIE, 7th International Symposium on Laser Metrology Applied to Science, Industry, and Everyday Life, 4900, 173-177, Sep. 2002, Peer-reviwed
International conference proceedings, English

Frequency-multiplexed profilometric phase coding for three-dimensional object recognition without 2 mu phase ambiguity
D Choudhury; M Takeda
OPTICS LETTERS, OPTICAL SOC AMER, 27, 16, 1466-1468, Aug. 2002, Peer-reviwed, A novel phase-coding technique based on Fourier-transform profilometry (FTP) is proposed for three-dimensional object recognition. Two spatially multiplexed grating patterns of different spatial frequencies are projected simultaneously onto the objects-target, and the phase changes in the distorted patterns are detected. An algebraic addition or subtraction of these phase values is utilized to code the two-dimensional plans of the objects-target with spatial harmonic modulations. The phase-coded plans of the objects and the target are cross correlated digitally to yield a high correlation peak at the target location. The 2pi ambiguity of the phase associated with FTP has been resolved in correlation results without recourse to phase unwrapping. Experimental results show an excellent discrimination capability for target recognition. (C) 2002 Optical Society of America.
Scientific journal, English

Simultaneous three-dimensional step-height measurement and high-resolution tomographic imaging with a spectral interferometric microscope
DS Mehta; M Sugai; H Hinosugi; S Saito; M Takeda; T Kurokawa; H Takahashi; M Ando; M Shishido; T Yoshizawa
APPLIED OPTICS, OPTICAL SOC AMER, 41, 19, 3874-3885, Jul. 2002, Peer-reviwed, A noncontact, nonmechanical scanning, wide-field spectral interference microscope is developed for simultaneous measurement of three-dimensional step-height of discontinuous objects and tomographic imaging. A superluminescent diode (SLD) is used as a broadband light source and a liquid-crystal Fabry-Perot interferometer (LC-FPI) as a frequency-scanning device. By means of changing the injection current to the SLD, the spectral profile of the SLD is equalized, and a constant light input to the interferometer is achieved over the entire frequency-scan range. The Fourier-transform technique is used to determine both the amplitude and the phase of spectral fringe signals. The three-dimensional height distribution of a discontinuous object is obtained from the phase information, whereas optically sectioned images of the object are obtained either from the amplitude information alone or from the combination of both the amplitude and phase information. Experimental results with submicrometer resolution are presented for both step-height measurement and tomographic sectioning. (C) 2002 Optical Society of America.
Scientific journal, English

Generation of femtosecond laser pulse with phase singularity
Y. Miyamoto; N. R. Heckenberg; H. Rubinsztein-Dunlop; A. Wada; T. Ohtani; N. Nishihara; M. Takeda
International Quantum Electronics Conference 2002, 59, Jun. 2002, Peer-reviwed
International conference proceedings, English

Synthesis of longitudinal coherence functions by spatial modulation of an extended light source: a new interpretation and experimental verifications
W Wang; H Kozaki; J Rosen; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 41, 10, 1962-1971, Apr. 2002, Peer-reviwed, Giving a new physical interpretation to the principle of longitudinal coherence control, we propose an improved method for synthesizing a spatial coherence function along the longitudinal axis of light propagation. By controlling the irradiance of an extended quasi-monochromatic spatially incoherent source with a spatial light modulator, we generated a special optical field that exhibits high coherence selectively for a specific pair of points at specified locations along the axis of beam propagation. This function of longitudinal coherence control provides new possibilities for dispersion-free measurements in optical tomography and profilometry. A quantitative experimental proof of principle is presented. (C) 2002 Optical Society of America.
Scientific journal, English

Three-dimensional step-height measurement using Mirau-type spectral interference microscope with acousto-optic tunable filter as frequency scanning device
DS Mehta; S Saito; H Hinosugi; M Takeda; T Kurokawa
INTERFEROMETRY XI: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 4777, 184-193, 2002, Peer-reviwed, We propose a non-mechanical scanning Mirau-type spectral interference microscopic imaging system for the measurement of three-dimensional step-height of discontinuous objects. In this system a superluminescent diode is used as a broad-band light source, and an acousto-optic tunable filter (AOTF) as a high-resolution frequency scanning device. The interferometric system was made unbalanced by putting the reference mirror position exactly half-way between the top and bottom of the total step-height of the discontinuous object. While scanning the frequency of the broad-band light source using AOTF, the interference fringes move in opposite directions on the top and bottom of the object, respectively. A two-dimensional Fourier transform method was used for the unique determination of the sign of fringe movement over a large area of the object without any photo-detectors and fringe counters. From the detected sign of the fringe movement and phase information, the three-dimensional step-height is measured. Experimental results of the measurement of 100mum step-height are presented. The main advantages of the proposed system are non-mechanical scanning and large measurement range without ambiguity in the sign of phase.
International conference proceedings, English

Reflectometry based on two-photon absorption of a silicon avalanche photodiode
Y Tanaka; PG Chua; T Kurokawa; H Tsuda; M Naganuma; M Takeda
OFS 2002: 15TH OPTICAL FIBER SENSORS CONFERENCE TECHNICAL DIGEST, IEEE, 577-580, 2002, Peer-reviwed
International conference proceedings, English

Effects of astigmatic aberration in holographic generation of Laguerre-Gaussian beam
A Wada; Y Miyamoto; T Ohtani; N Nishihara; M Takeda
ADVANCED LASERS AND SYSTEMS, SPIE-INT SOC OPTICAL ENGINEERING, 5137, 177-180, 2002, Peer-reviwed, The Laguerre-Gaussian (LG) beam is an optical beam with a phase singularity that propagates along its axis. We have studied the effect of astigmatic aberration on LG beams through numerical simulation and experiment.
An LG beam with astigmatic aberration can undergo various transformations. An LG beam with astigmatic aberration can be expanded in terms of Hermite-Gaussian(HG) beams whose horizontal and vertical axes are aligned with the axes of the astigmatism. By redefining the expansion coefficients to include the Gouy phase of the HG beams, the coefficients can be reduced to a single parameter that depends on the propagation distance. It can be shown that the various transformations of the LG beam is governed by this parameter. This presents us with a simple method of estimating the beam profile and positions of the split phase singularities at any given propagation distance. The estimations show good agreement with intensity and phase distributions calculated with the angular spectrum method.
International conference proceedings, English

Synthetic spatial coherence function for optical tomography and profilometry: simultaneous realization of longitudinal coherence scan and phase shift
ZH Duan; M Gokhler; J Rosen; H Kozaki; N Ishii; M Takeda
INTERFEROMETRY XI: TECHNIQUES AND ANALYSIS, SPIE-INT SOC OPTICAL ENGINEERING, 4777, 110-117, 2002, Peer-reviwed, A new scheme for synthesizing three-dimensional longitudinal spatial coherence function is proposed. By manipulating the irradiance of an extended quasi-monochromatic spatially incoherent source with a spatial light modulator, we generated a special optical field that exhibits high coherence selectively for the specified location along the optical axis of propagation and for the specified inclination between the two mirrors in the interferometer. The feasibility of the proposed principle is demonstrated by measuring a step height made by standard gauge blocks. The proposed scheme permits one to perform phase shift without recourse to mechanical movement. The quantitative experimental proof of the principle is presented.
International conference proceedings, English

Multiple-wavelength optical vortices
Y. Miyamoto; A. Wada; T. Ohtani; N. Nishihara; M. Takeda; H. Rubinsztein-Dunlop; N. R. Heckenberg
Proc. Australasian Conference on Optics, Lasers and Spectroscopy 2001, (Brisbane, Australia), 51, Dec. 2001, Peer-reviwed
International conference proceedings, English

Propagation characteristics of laser beam with phase singularity under presence of astigmatism
Y. Miyamoto; A. Wada; T. Ohtani; N. Nishihara; M. Takeda
Multi-dimensional Microscopy 2001, the 3rd Asia-Pacific Symposium on Confocal Microscopy and Related Technologies, (Melbourne, Australia), 52, Nov. 2001, Peer-reviwed
International conference proceedings, English

Three-dimensional shape measurement and tomographic imaging of discontinuous objects using spectral interferometric technique with improved resolution
D. S. Mehta; M. Sugai; H. Hinosugi; S. Saito; M. Takeda; T. Kurokawa; H. Takahashi; M. Ando; M. Shishido; Y. Yoshizawa
Fringe 2001, Proceedings of the 4th International Workshop on Automatic Processing of Fringe Patterns (Bremen, Germany), 341-343, Sep. 2001, Peer-reviwed
International conference proceedings, English

"Evolution of Optical Vortices and Phase Singularities in Scattered Random Fields: -Experimental Observation of Their 3-D Structures-"
T. Sotomaru; H. Tsuchiya; Y. Miyamoto; M. Takeda
International Balatonfuered Workshop on New Prospectives for Optical Metrology, HoloMet 2001 (Baratonfuered, Hungary, June 2001), 75-81, Jun. 2001
International conference proceedings, English

Coordinate-transform technique for closed-fringe analysis by the Fourier-transform method
ZT Ge; F Kobayashi; S Matsuda; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 40, 10, 1649-1657, Apr. 2001, Peer-reviwed, A coordinate-transform technique is proposed that enables the Fourier-transform method to analyze an interferogram that includes a closed-fringe pattern. First, the closed-fringe pattern is converted to an open-fringe pattern by transformation of the Cartesian coordinate system to a polar coordinate system. Then the phase distribution for the open-fringe interferogram is determined by the conventional Fourier-transform method. The phase distribution for the original closed-fringe pattern is obtained by inverse coordinate transformation from the polar coordinate system back to the Cartesian coordinate system. Computer simulation and experiments were performed for a closed-fringe pattern generated by interference of a spherical wave with a reference plane wave, and results are presented that demonstrate the validity of the proposed technique. (C) 2001 Optical Society of America.
Scientific journal, English

Self-reference method for phase-shift interferometry
ZT Ge; M Takeda
OPTICAL ENGINEERING FOR SENSING AND NANOTECHNOLOGY (ICOSN 2001), SPIE-INT SOC OPTICAL ENGINEERING, 4416, 152-157, 2001, A self-reference method (SRM) is proposed to realize high precision fringe analysis for phase-shifting interferometry when translation and tilt errors exist in phase shifters. In this method, arbitrary pixel-dependent phase shifts including those caused by tilt are directly estimated from a single interferogram by the Fourier transform method without using any extra reference mirror. The obtained phase shifts are then used to reconstruct the original wave front according to the algorithm of the proposed self-reference method. Computer simulations demonstrate the feasibility of the proposed method. Precision of shifted phases and tilts estimation is also evaluated, and some error sources are analyzed. It is shown that the self-reference 3-step method can give better accuracy than that of the popular 5-step method even when the tilt error exists in the reference surface.
International conference proceedings, English

Effects of astigmatic aberration in holographic generation of Laguerre-Gaussian beam.
A Wada; Y Miyamoto; T Ohtani; N Nishihara; M Takeda
OPTICAL ENGINEERING FOR SENSING AND NANOTECHNOLOGY (ICOSN 2001), SPIE-INT SOC OPTICAL ENGINEERING, 4416, 376-379, 2001, Peer-reviwed, The Laguerre-Gaussian (LG) beam is an optical beam with a phase singularity that propagates along its axis. We have, previously reported the fabrication of blazed transmission phase holograms to generate beams with phase singularities. A common problem encountered in the generation of a phase singularity with high charge is that the singularity tends to split into m individual charge 1 singularities. where nz is the charge of the original singularity.
We have found through numerical simulation that astigmatic aberration call cause a higher-charge phase singularity to split. We have also found that strong astigmatic aberrations make the resulting beam close to a Hermite-Gaussian beam rather than a LG beam. Experimental investigation of these phenomena agree with the numerical simulation.
International conference proceedings, English

Spectral interferometric technique for 3D-shape measurement of microscopic objects with improved resolution, speed of measurement and signal processing
DS Mehta; M Sugai; H Hinosugi; S Saito; M Takeda; T Kurokawa; H Takahashi; M Ando; M Shishido; T Yoshizawa
CLEO(R)/PACIFIC RIM 2001, VOL I, TECHNICAL DIGEST, IEEE, I, 472-473, 2001, Peer-reviwed, A spectral interference microscope using superluminescent diode as light source and a liquid-crystal Fabry-Perot etalon as a frequency tunable device is developed for three-dimensional imaging micro-profilometry. By changing the current to the superluminescent diode the constant light input to the interferometer was achieved throughout the measurement. A high speed Fourier transform technique was developed for the analysis of the data which takes few seconds to measure the three-dimensional absolute height distribution of a discontinuous object. Experimental results with improved resolution and speed of measurement are presented.
International conference proceedings, English

Infra-red image detection with a Si-CCD image sensor due to the two-photon absorption process
PG Chua; Y Tanaka; M Takeda; T Kurokawa
CLEO(R)/PACIFIC RIM 2001, VOL I, TECHNICAL DIGEST, IEEE, I, 482-483, 2001, Peer-reviwed, Infra-red images were captured by a Si-CCD image sensor. The Si-CCD showed quadratic sensitivity characteristics due to the two-photon absorption process for the high intensity light with a wavelength of 1550 nm.
International conference proceedings, English

High precision 2-D angle measurement using fringe analysis techniques
ZT Ge; T Saito; S Matsuda; M Takeda
OPTICAL MANUFACTURING AND TESTING IV, SPIE-INT SOC OPTICAL ENGINEERING, 4451, 448-457, 2001, Peer-reviwed, In this paper, a novel angle measurement method using the fringe analysis techniques is proposed. In this method, a 2-D surface profile including a tilt is obtained by fringe analysis, and the tilt in the 2-D surface profile is determined by fitting the obtained surface profile with a plane. From the fitted plane, 2-D angles can be easily obtained. Simulations using the Fourier transform and phase-shift methods are performed, and the results are compared with each other. Simulations show that 2-D angle measurement using the fringe analysis techniques can achieve simultaneously a wide measurement range and high precision.
International conference proceedings, English

New principle for optical tomography and profilometry based on spatial coherence synthesis with a spatially modulated extended light source
W Wang; H Kozaki; J Rosen; M Takeda
ADVANCED PHOTONIC SENSORS AND APPLICATIONS II, SPIE-INT SOC OPTICAL ENGINEERING, 4596, 54-65, 2001, Peer-reviwed, Giving a new physical interpretation to the principle of longitudinal coherence control, we propose an improved method for synthesizing a desired spatial coherence function along the longitudinal axis of light propagation. By controlling the irradiance of an extended quasi-monochromatic spatially incoherent source with a spatial light modulator, we generated a special optical field that exhibits high coherence selectively for the particular pair of points at the specified locations along the axis of beam propagation. This function of longitudinal coherence control provides new possibilities in optical tomography and profilometry. Quantitative experimental proof of the principle is presented.
International conference proceedings, English

Holographic generation of Laguerre-Gaussian beam: effect of illumination beam properties
A. Wada; Y. Miyamoto; T. Ohtani; M. Masuda; M. Takeda
Proc. 2nd International Conference on Optical Design and Fabrication, ODF2000,（Tokyo, Japan）, 181-184, Nov. 2000, Peer-reviwed
International conference proceedings, English

Holographic generation of laser beam with phase singularity
Y. Miyamoto; A. Wada; T. Ohtani; M. Masuda; M. Takeda
2000 Conference on Lasers and Electro-Optics Europe, 88, Sep. 2000, Peer-reviwed
International conference proceedings, English

Longitudinal spatial coherence applied for surface profilometry
J Rosen; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 39, 23, 4107-4111, Aug. 2000, Peer-reviwed, A method of optical coherence profilometry, believed to be new, is demonstrated. This method is based on the spatial, rather than the temporal, coherence phenomenon. Therefore the proposed interferometric system is illuminated by a quasi-monochromatic spatial incoherent source instead of a broadband Light source. The surface profile is measured by means of shifting the spatial degree of coherence gradually along its longitudinal axis while keeping the optical path difference between the measured surface and a reference plane constant. Experimental proof of the new principle is presented. (C) 2000 Optical Society of America OCIS codes: 110.4500, 120.3180, 050.1950, 100.6950, 030.1640, 120.6660.
Scientific journal, English

Interferometric microimaging based on geometrical spin-redirection phase
AV Tavrov; Y Miyamoto; T Kawabata; M Takeda; VA Andreev
OPTICS LETTERS, OPTICAL SOC AMER, 25, 7, 460-462, Apr. 2000, Peer-reviwed, A novel scheme for an interferometric microscope with which to visualize a geometrical spin-redirection phase image that represents the local inclination of microsurface structures of an object is proposed. The observed phase depends on the state of polarization and the optical constants of the object material, which enable one to distinguish the spin-redirection phase from the conventional dynamical-phase. A preliminary experiment was performed, and the phase images obtained were found to be consistent with those predicted by computer simulation based on a theoretical model. (C) 2000 Optical Society of America OCIS codes: 120.3180, 120.2130, 080.2730, 120.0120, 10.5050.
Scientific journal, English

Imaging with Berry phase in polarization interferometer with geometric shear
A. V. Tavrov; Y. Miyamoto; T. Kawabata; M. Takeda; V. A. Andreev
FOM 2000, International Workshop on Focus on Microscopy（Shirahama, Japan）, 44, Apr. 2000, Peer-reviwed
International conference proceedings, English

Absolute three-dimensional shape measurements using coaxial and coimage plane optical systems and Fourier fringe analysis for focus detection
M Takeda; T Aoki; Y Miyamoto; H Tanaka; RW Gu; ZB Zhang
OPTICAL ENGINEERING, SPIE-INT SOCIETY OPTICAL ENGINEERING, 39, 1, 61-68, Jan. 2000, Peer-reviwed, For the absolute and shade-free shape measurement of 3-D objects with large height discontinuities, a coaxial optical sensor system with a common image plane for pattern projection and observation is proposed. Experimental results are presented that demonstrate the shape measurements of objects with a deep hole and large discontinuities. (C) 2000 Society of Photo-Optical instrumentation Engineers. [S0091-3286(00)00701-7].
Scientific journal, English

Generalized algorithm for the unified analysis and simultaneous evaluation of geometrical spin-redirection phase and Pancharatnam phase in a complex interferometric system
AV Tavrov; Y Miyamoto; T Kawabata; M Takeda; VA Andreev
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 17, 1, 154-161, Jan. 2000, Peer-reviwed, To permit unified analysis and simultaneous evaluation of geometrical spin-redirection phase and Pancharatnam phase, the conventional 2 x 2 Jones matrix calculation is generalized and a new scheme of 3 x 3 matrix calculation is proposed. With the proposed algorithm one can trace the polarization state changes and the geometric phase shifts caused by beam propagation along an arbitrary optical path that involves both reflection and refraction at surfaces with Fresnel shift and birefringence. (C) 2000 Optical Society of America [S0740-3232(00)01801-9].
Scientific journal, English

Visualisation of Berry spin-redirection phase in polarization interferometer with geometric shear
AV Tavrov; Y Miyamoto; T Kawabata; M Takeda; VA Andreev
LASER INTERFEROMETRY X: TECHNIQUES AND ANALYSIS AND APPLICATIONS, PTS A AND B, SPIE-INT SOC OPTICAL ENGINEERING, 4101, 12-20, 2000, A novel scheme of an interferometric microscope is proposed to visualize a geometrical spill-redirection phase image that represents the local inclination of micro surface structures of an object. The observed phase depends on the state of polarization and optical constants of the object material, which enables one to distinguish the spin-redirection phase from the conventional dynamical phase. A preliminary experiment was performed, and the phase images obtained were found to be consistent with those predicted by computer simulation based on a theoretical model.
International conference proceedings, English

Coordinate transform method for closed fringe analysis
ZT Ge; F Kobayashi; S Matsuda; M Takeda
LASER INTERFEROMETRY X: TECHNIQUES AND ANALYSIS AND APPLICATIONS, PTS A AND B, SPIE-INT SOC OPTICAL ENGINEERING, 4101, 38-46, 2000, Peer-reviwed, A coordinate transform method is proposed which enables the Fourier transform method to analyze interferograms including closed hinge patterns. According to the principle of the proposed method, closed fringe patterns in an interferogram can be converted to open fringe patterns by transforming the Cartesian coordinate system to a polar coordinate system. Phases corresponding to the open fringe interferograms can be obtained by analyzing the open fringe interferograms using the conventional Fourier transform method. Subsequently, the original phases corresponding to the closed fringe interferograms can be acquired by inverse coordinate transform. Computer simulation and experiments show that spherical wave fronts are accurately recovered by using the proposed method.
International conference proceedings, English

Optical frequency-domain imaging microprofilometry with a frequency-tunable liquid-crystal Fabry-Perot etalon device
N Kinoshita; M Takeda; H Yago; Y Watanabe; T Kurokawa
APPLIED OPTICS, OPTICAL SOC AMER, 38, 34, 7063-7068, Dec. 1999, Peer-reviwed, An optical frequency-domain interference microscope with a liquid-crystal Fabry-Perot interferometer as an optical frequency-scan device was developed for microscopic three-dimensional shape measurements. The proposed system can perform absolute measurement of the discontinuous surface profile of a microscopic object without use of mechanically moving components such as a piezoelectric transducer or a grating spectrometer. Experimental results are presented that demonstrate the validity of the principle. (C) 1999 Optical Society of America OCIS codes: 120.3180, 120.2830, 120.3930, 120.2230, 120.3940, 120.2650.
Scientific journal, English

Method to evaluate the geometrical spin-redirection phase for a nonplanar ray
AV Tavrov; T Kawabata; Y Miyamoto; M Takeda; VV Andreev
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 16, 4, 919-921, Apr. 1999, Peer-reviwed, An evaluation method is suggested for determining the Berry geometrical spin-redirection phase in systems with a set of separated optical elements. The evaluation considers the coordinate transformation, taking into account the directions of the beam. The spin-redirection phase contains information about the nonplanarity of beam propagation. This geometrical phase can be determined even if the ray trajectory is traced as an unclosed topological contour on the unit sphere associated with wave-vector directions. (C) 1999 Optical Society of America [S0740-3232(99)00204-5].
Scientific journal, English

Photonic sensing and metrology using novel liquid crystal devices
M Takeda; T Kurokawa
SELECTED PAPER FROM INTERNATIONAL CONFERENCE ON OPTICS AND OPTOELECTRONICS '98, SPIE-INT SOC OPTICAL ENGINEERING, 3729, 415-425, 1999, Peer-reviwed, Novel liquid crystal devices originally developed for photonic information processing and optical communication have found new applications in photonic sensing and metrology. The paper reviews our recent studies on real-time vibrometry using a fast ferroelectric liquid crystal spatial light modulator, and three-dimensional micro shape measurements using a frequency-tunable liquid crystal Fabry-Perot interferometer.
International conference proceedings, English

Electron-beam lithography fabrication of phase holograms to generate Laguerre-Gaussian beams
Y Miyamoto; M Masuda; A Wada; M Takeda
OPTICAL ENGINEERING FOR SENSING AND NANOTECHNOLOGY (ICOSN'99), SPIE-INT SOC OPTICAL ENGINEERING, 3740, 232-235, 1999, Peer-reviwed, The Laguerre-Gaussian beam is an optical beam with a phase singularity that propagates along its axis. We have fabricated blazed phase holograms to generate these beams using electron-beam lithography techniques. The resulting holograms were illuminated with a Gaussian beam, and the phase distribution of the resulting beams were examined by analyzing interference fringes with the Fourier-transform method.
International conference proceedings, English

3-D shape measurement using a coaxial and coimage-plane fringe projection and observation system
M Takeda; T Aoki; Y Miyamoto; H Tanaka; RW Gu; ZB Zhang
INTERFEROMETRY '99: TECHNIQUES AND TECHNOLOGIES, SPIE-INT SOC OPTICAL ENGINEERING, 3744, 126-135, 1999, Peer-reviwed, For the absolute and shade-free shape measurement of three-dimensional objects with large height discontinuities, a co-axial optical sensor system with a common image plane for pattern projection and observation was proposed. Experimental results are presented that demonstrate the shape measurements of objects with a deep hole and large discontinuities.
International conference proceedings, English

Efficient algorithm for the evaluation of geometric shift of polarization in interferometric and polarimetric systems
AV Tavrov; Y Miyamoto; T Kawabata; M Takeda; VV Andreev
INTERFEROMETRY '99: TECHNIQUES AND TECHNOLOGIES, SPIE-INT SOC OPTICAL ENGINEERING, 3744, 347-357, 1999, Peer-reviwed, To enable unified analysis and simultaneous evaluation of geometrical spin-redirection phase and Pancharatnam phase, conventional 2 x 2 Jones matrix calculation is generalized and a new scheme of 3 x 3 matrix calculation is proposed. By the proposed algorithm one can trace the polarization state changes and the geometric phase shifts caused by the beam propagation along an arbitrary optical path that involves both reflection and refraction at surfaces with Fresnel shift and birefringence.
International conference proceedings, English

Real-time holographic vibrometry with a ferroelectric liquid-crystal spatial light modulator
M. Sano; M. Takeda; S. Fukushima; T. Kurokawa
Appl. Opt., 37, 32, 32, Dec. 1998
Scientific journal, English

Two-dimensional phase unwrapping by direct elimination of rotational vector fields from phase gradients obtained by heterodyne technigues
T. Aoki; T. Sotomaru; Y. Miyamoto; M. Takeda
Laser Interferometry IX : Techniques and Analysis, Proc. SPIE, 3478, 162-168, Jul. 1998, Peer-reviwed
International conference proceedings, English

Implementation of geometrical spin-redirection phase in inter ferometric measurements
A. V. Tavrov; M. Takeda; Y. Miyamoto; T.Kawabata; V. V. Andree
Conference on Laser Optics 98, Paper N. 1112 22-26, Jun. 1998, Peer-reviwed
International conference proceedings, English

Two-dimensional phase unwrapping by direct elimination of rotational vector fields from phase gradients obtained by heterodyne techniques
Takahiro Aoki; Toshihiro Sotomaru; Takeshi Ozawa; Takashi Komiyama; Yoko Miyamoto; Mitsuo Takeda
Optical Review, Optical Society of Japan, 5, 6, 374-379, 1998, Peer-reviwed, Noting the analogy between electro-magnetic fields and the vector fields of phase gradients obtained by heterodyne techniques, we propose a new algorithm for least-squares phase unwrapping. Instead of solving a Poisson equation for the unwrapped phase map or using Green's formulation, we directly remove singular points or residues from the measured phase map by superposing sign-reversed vortex fields which cancel out the rotational vector fields associated with the phase singular points.
Scientific journal, English

Frequency-multiplex Fourier-transform profilometry: A single-shot three-dimensional shape measurement of objects with large height discontinuities and/or surface isolations
M Takeda; Q Gu; M Kinoshita; H Takai; Y Takahashi
APPLIED OPTICS, OPTICAL SOC AMER, 36, 22, 5347-5354, Aug. 1997, Peer-reviwed, The performance of Fourier-transform profilometry is enhanced by a new technique that is based on spatial frequency multiplexing combined with the Gushov-Solodkin phase unwrapping algorithm. The technique permits the three-dimensional shape measurement of objects that have discontinuous height steps and/or spatially isolated surfaces, which has not been possible by conventional Fourier-transform profilometry. An important feature of the technique is that it requires only a single fringe pattern; the single-shot recording makes possible the instantaneous three-dimensional shape measurement of discontinuous objects in fast motion. Experimental results are presented that demonstrate the validity of the principle. (C) 1997 Optical Society of America.
Scientific journal, English

Phase unwrapping by a maximum cross-amplitude spanning tree algorithm: A comparative study
M Takeda; T Abe
OPTICAL ENGINEERING, SOC PHOTO-OPT INSTRUM ENG, 35, 8, 2345-2351, Aug. 1996, Peer-reviwed, A comparative study is made of phase-unwrapping algorithms that adopt either phase gradients or fringe amplitudes as a reliability measure in the selection of an unwrapping path. To compare with the minimum-phase-gradient spanning-tree algorithm, a maximum cross-amplitude spanning-tree algorithm is proposed, which seeks a spanning tree that maximizes overall edge weights given by the cross-amplitudes, i.e., the products of the fringe amplitudes of neighboring pixels. Noise immunity of the cross-amplitude spanning-tree algorithm is demonstrated by experiment and computer simulation. (C) 1996 Society of Photo-Optical Instrumentation Engineers.
Scientific journal, English

Diffraction efficiency of a grating coupler for an array illuminator
T Nakaya; Y Katoh; T Kubota; M Takeda
APPLIED OPTICS, OPTICAL SOC AMER, 35, 20, 3891-3898, Jul. 1996, Peer-reviwed, The diffraction efficiency of a grating coupler having a surface-relief grating is calculated by the use of coupled-wave theory. The grating couplers are fabricated to examine the validity of the calculated result. The dependence of the measured diffraction efficiency on the groove depth of the grating coupler agrees well with the calculated results. The array illuminator, which emits 10 and 20 beams with equal intensity, is designed and fabricated through the use of these numerical results. The uniformity error of the output beam caused by the error of the diffraction efficiency is also discussed. (C) 1996 Optical Society of America
Scientific journal, English

Crystallographic heterodyne phase detection for highly sensitive lattice-distortion measurements
M Takeda; J Suzuki
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 13, 7, 1495-1500, Jul. 1996, Peer-reviwed, Noting the structural similarity between a distorted lattice in a crystal and a spatially phase-modulated fringe pattern in optical metrology, we propose a crystallographic lattice heterodyne technique. The technique detects lattice distortions as spatial phase modulations, where the phase change by 2 pi corresponds to the displacement of atoms or lattice points by a distance equal to the lattice constant. By virtue of heterodyne detection, the technique has the potential for determining the lattice distortions to several hundredths of the lattice constant. (C) 1996 Optical Society of America.
Scientific journal, English

Rice probability functions for level-crossing intervals of speckle intensity fields
N Youssef; T Munakata; M Takeda
OPTICS COMMUNICATIONS, ELSEVIER SCIENCE BV, 123, 1-3, 55-62, Jan. 1996, Peer-reviwed, Statistics of level-crossing intervals of an intensity distribution of monochromatic speckle patterns is studied. Rice probability functions are derived for the space intervals between the crossings occurring at an arbitrary intensity level of the speckle patterns. Numerical examples of the Rice probability functions are presented for the speckle patterns whose spatial frequency spectrum is limited by ideal rectangular and Gaussian low-pass spatial frequency filters.
Scientific journal, English

GENERATION OF A VIRTUAL WAVE-FRONT BY SPACE-TIME DEGENERACY IN A SCAN-SYNCHRONIZED WAVELENGTH-SHIFT INTERFEROMETER
M TAKEDA; JI HASE
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 12, 12, 2686-2692, Dec. 1995, Peer-reviwed, A new concept of the virtual wave front is introduced, and a principle of generating a virtual wave front by using space-time degeneracy in a scan-synchronized wavelength-shift interferometer is proposed. Results of preliminary experiments are presented to demonstrate the validity of the principle, and some applications of the virtual wave fronts are suggested. (C) 1995 Optical Society of America.
Scientific journal, English

FOURIER-TRANSFORM SPECKLE PROFILOMETRY - 3-DIMENSIONAL SHAPE MEASUREMENTS OF DIFFUSE OBJECTS WITH LARGE HEIGHT STEPS AND/OR SPATIALLY ISOLATED SURFACES
M TAKEDA; H YAMAMOTO
APPLIED OPTICS, OPTICAL SOC AMER, 33, 34, 7829-7837, Dec. 1994, Peer-reviwed, An interferometric technique for automated profilometry of diffuse objects has been proposed. It is based on the Fourier-fringe analysis of spatiotemporal specklegrams produced by a wavelength-shift interferometer with a laser diode as a frequency-tunable light source. Unlike conventional moire techniques the proposed technique permits the objects to have discontinuous height steps and/or surfaces spatially isolated from one another. Experimental results are presented that demonstrate the validity of the principle.
Scientific journal, English

FOURIER-TRANSFORM SPECKLE PROFILOMETRY - 3-DIMENSIONAL SHAPE MEASUREMENTS OF DIFFUSE OBJECTS WITH LARGE HEIGHT STEPS AND/OR SPATIALLY ISOLATED SURFACES
M TAKEDA; H YAMAMOTO
APPLIED OPTICS, OPTICAL SOC AMER, 33, 34, 7829-7837, Dec. 1994, Peer-reviwed, An interferometric technique for automated profilometry of diffuse objects has been proposed. It is based on the Fourier-fringe analysis of spatiotemporal specklegrams produced by a wavelength-shift interferometer with a laser diode as a frequency-tunable light source. Unlike conventional moire techniques the proposed technique permits the objects to have discontinuous height steps and/or surfaces spatially isolated from one another. Experimental results are presented that demonstrate the validity of the principle.
Scientific journal, English

STACK-TYPE OPTICAL BUSLINES BASED ON A MODIFIED DRAGONE STAR COUPLER - A CONCEPT
M TAKEDA
OPTOELECTRONICS-DEVICES AND TECHNOLOGIES, MITA PRESS, 9, 1, 137-142, Mar. 1994, Peer-reviwed, A concept of a stack-type optical busline using a modified Dragone star coupler is proposed. While the Dragone coupler performs N x N connections between two arrays of N channel waveguides, its modified version has the function of a busline which can perform full 2N x 2N connections between all the 2N channel waveguides including the connections between those located in the same array. A scheme for an inter-layer optical busline using a modified Dragone star coupler is suggested.
Scientific journal, English

COMPLEX NEURAL FIELDS WITH A HOPFIELD-LIKE ENERGY FUNCTION AND AN ANALOGY TO OPTICAL-FIELDS GENERATED IN PHASE-CONJUGATE RESONATORS
M TAKEDA; T KISHIGAMI
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 9, 12, 2182-2191, Dec. 1992, Peer-reviwed, A complex phase-conjugate neural network model with a Hopfield-like energy function has been proposed, and a physical interpretation is given to its dynamics. Unlike Noest's phasor neuron model with a fixed amplitude, the complex neural fields of the proposed model can change both the amplitude and the phase, and their dynamics has a close analogy with the dynamics of self-oscillation generated in a phase-conjugate resonator. From the analysis of the dynamics, it was found that the optical-gain medium should have a phase-conjugate property in order for the generated complex optical fields to have an energy function that decreases monotonically with the time evolution of the fields. The results of experiments and computer simulations are presented that demonstrate the behaviors of the complex neural fields that are predicted by the theory.
Scientific journal, English

SPATIOTEMPORAL FREQUENCY MULTIPLEX HETERODYNE INTERFEROMETRY
M TAKEDA; M KITOH
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, OPTICAL SOC AMER, 9, 9, 1607-1614, Sep. 1992, Peer-reviwed, To have the advantages of both spatial and temporal heterodyne techniques and to make efficient use of the limited spatiotemporal frequency bandwidth of image detection systems, we propose a technique of spatiotemporal heterodyne interferometry using both spatial and temporal carrier frequencies. By means of spatiotemporal frequency multiplexing, the technique permits the simultaneous recording of multiple-phase objects on a single space-time interferogram.
Scientific journal, English

WAVELENGTH-SHIFT INTERFEROMETRY FOR DISTANCE MEASUREMENTS USING THE FOURIER-TRANSFORM TECHNIQUE FOR FRINGE ANALYSIS
M SUEMATSU; M TAKEDA
APPLIED OPTICS, OPTICAL SOC AMER, 30, 28, 4046-4055, Oct. 1991, Peer-reviwed, The Fourier transform technique, originally developed for spatial fringe pattern analysis, has been applied to the analysis of a temporal fringe signal obtained by a wavelength-shift interferometer used for absolute distance measurements. It has been shown that the error caused by the nonlinear and time-varying current-wavelength characteristic of the laser diode can be removed by combining the Fourier transform technique with the reference technique. A novel technique for distance measurement based on multiple-beam interferometry has been proposed, and an experimental demonstration is given for a three-beam interferometer that includes a reference reflector as an integral part of the system. Error sources and the limitation of the technique are discussed.
Scientific journal, English

INTEGRATED OPTIC ARRAY ILLUMINATOR - A DESIGN FOR EFFICIENT AND UNIFORM POWER DISTRIBUTION
M TAKEDA; T KUBOTA
APPLIED OPTICS, OPTICAL SOC AMER, 30, 9, 1090-1095, Mar. 1991, Peer-reviwed, A design principle for an integrated optic array illuminator is presented, and an array illuminator which can generate uniform beams with 100% power efficiency has been designed. It was found that there exists a trade-off relationship between the beam compression ratio and the maximum number of beams available. Based on this relationship, the possibility and limitation of the proposed scheme are discussed.
Scientific journal, English

Spatial-carrier fringe-pattern analysis and its applications to precision interferometry and profilometry: An overview
Mitsuo Takeda
Industrial Metrology, 1, 2, 79-99, 1990, Peer-reviwed, The principle of the spatial-carrier heterodyne technique is described with emphasison fringe-pattern analysis. Characteristics of the spatial-carrier technique and the temporal-carrier technique are compared, and the relationship between the two techniques is clarified. Recent developments in the spatial-carrier fringe-pattern analysis techniques and their application areas are reviewed. © 1990 Elsevier Science Publishers B.V.
Scientific journal, English

ARRAY ILLUMINATOR USING GRATING COUPLERS
T KUBOTA; M TAKEDA
OPTICS LETTERS, OPTICAL SOC AMER, 14, 12, 651-652, Jun. 1989, Peer-reviwed
Scientific journal, English

PHASE RETRIEVAL BASED ON THE IRRADIANCE TRANSPORT-EQUATION AND THE FOURIER-TRANSFORM METHOD - EXPERIMENTS
K ICHIKAWA; AW LOHMANN; M TAKEDA
APPLIED OPTICS, OPTICAL SOC AMER, 27, 16, 3433-3436, Aug. 1988, Peer-reviwed
Scientific journal, English

NEURAL NETWORKS FOR COMPUTATION - NUMBER REPRESENTATIONS AND PROGRAMMING COMPLEXITY
M TAKEDA; JW GOODMAN
APPLIED OPTICS, OPTICAL SOC AMER, 25, 18, 3033-3046, Sep. 1986, Peer-reviwed
Scientific journal, English

SUBFRINGE HOLOGRAPHIC-INTERFEROMETRY BY COMPUTER-BASED SPATIAL-CARRIER FRINGE-PATTERN ANALYSIS
M TAKEDA; Z TUNG
JOURNAL OF OPTICS-NOUVELLE REVUE D OPTIQUE, MASSON EDITEUR, 16, 3, 127-131, 1985, Peer-reviwed
Scientific journal, English

COMPUTER-BASED HIGHLY SENSITIVE ELECTRON-WAVE INTERFEROMETRY
M TAKEDA; QS RU
APPLIED OPTICS, OPTICAL SOC AMER, 24, 18, 3068-3071, 1985, Peer-reviwed
Scientific journal, English

LATERAL ABERRATION MEASUREMENTS WITH A DIGITAL TALBOT INTERFEROMETER
M TAKEDA; S KOBAYASHI
APPLIED OPTICS, OPTICAL SOC AMER, 23, 11, 1760-1764, 1984, Peer-reviwed
Scientific journal, English

Optical design for three-mirror 120-inch telescopes and their prime focus corrector
H. W. Epps; M. Takeda
Kogaku, 応用物理学会分科会日本光学会, 13, 5, 400-409, 1984, Peer-reviwed
Scientific journal, Japanese

Optimization and practical designs for three-mirror telescopes
H. W. Epps; M. Takeda
Annals of the Tokyo Astronomical Observatory, 19, 3, 401-412, 1983, Peer-reviwed
Research institution, English

FOURIER-TRANSFORM PROFILOMETRY FOR THE AUTOMATIC-MEASUREMENT OF 3-D OBJECT SHAPES
M TAKEDA; K MUTOH
APPLIED OPTICS, OPTICAL SOC AMER, 22, 24, 3977-3982, 1983, Peer-reviwed
Scientific journal, English

FOURIER-TRANSFORM METHOD OF FRINGE-PATTERN ANALYSIS FOR COMPUTER-BASED TOPOGRAPHY AND INTERFEROMETRY
M TAKEDA; H INA; S KOBAYASHI
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA, AMER INST PHYSICS, 72, 1, 156-160, 1982, Peer-reviwed
Scientific journal, English

FRINGE FORMULA FOR PROJECTION TYPE MOIRE TOPOGRAPHY
M TAKEDA
OPTICS AND LASERS IN ENGINEERING, ELSEVIER SCI LTD, 3, 1, 45-52, 1982, Peer-reviwed
Scientific journal, English

MOIRE STEREOMICROSCOPE
M TAKEDA; H INA
JOURNAL OF OPTICS-NOUVELLE REVUE D OPTIQUE, IOP PUBLISHING LTD, 13, 6, 339-343, 1982, Peer-reviwed
Scientific journal, English

CHROMATIC ABERRATION MATCHING OF THE POLYCHROMATIC OPTICAL TRANSFER-FUNCTION
M TAKEDA
APPLIED OPTICS, OPTICAL SOC AMER, 20, 4, 684-687, 1981, Peer-reviwed
Scientific journal, English

NEW DIAGRAM FOR NOMOGRAPHIC DESIGN AND ANALYSIS OF PARAXIAL OPTICAL-SYSTEMS
M TAKEDA
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA, AMER INST PHYSICS, 70, 2, 236-242, 1980, Peer-reviwed
Scientific journal, English

MTF measurement of TV zoom lenses ; Influence of distortion on the equivalence of normal and inverse conjugate techniques
M. Takeda; K. Takesi
Appl. Opt., 17, 14, 2171-2175, Jul. 1978, Peer-reviwed
Scientific journal, English

Transmittance of a Gaussian beam through a Fabry-Perot etalon : Angular spectrum analysis and Experiments
芳野俊彦; 武田光夫
Kogaku, 6, 3, 113-119, Jun. 1977, Peer-reviwed
Scientific journal, Japanese

Influence of noise on the measurement of optical transfer functions by the digital Fourier transform method
M. Takeda; T. Ose
J. Opt. Soc. Am., 65, 5, 502-508, May 1975, Peer-reviwed
Scientific journal, English

Effect of phase nonlinearity in kinoform
T. Yatagai; M. Takeda
OPTIK, Zeitschrift fuer Licht-und Elekronenoptik, 43, 4, 337-352, Apr. 1975, Peer-reviwed
Scientific journal, English

Statistical error analysis of optical transfer functions obtained by the digital Fourier transform method
M. Takeda; T. Ose
Rept. of Institute of Industrial Science, Univ. of Tokyo, 24, 7, 289-317, 1975
Research institution, English

Efficient algorithm for OTF calculation by double transform method
武田光夫; 小瀬輝次
Kogaku, 3, 6, 373-382, Dec. 1974, Peer-reviwed
Scientific journal, Japanese

Effect of truncation of noisy line spread function on the computed optical transfer function
M. Takeda; T. Ose
Optica Acta, 21, 6, 477-487, Jun. 1974, Peer-reviwed
Scientific journal, English

Papers of Dr. Dinesh N. NAIK
TAKEDA Mitsuo
10 May 2013, 光学, 42, 5, 267-267, Japanese, 0389-6625, 10031166453, AN00080324

コヒーレンスホログラフィ：3次元空間コヒーレンス場の生成と制御
武田 光夫
Jan. 2013, 応用物理, 82, 1, 46-50, Japanese, Invited, Introduction scientific journal

先進的干渉計測技術の展望―計算光学とモデル同定干渉計測―
武田 光夫
光学工業技術協会, Jan. 2013, 光技術コンタクト, 51, 1, 21-28, Japanese, Invited, Introduction other, 0913-7289, 40019550820, AN10075091

19pAK-6 Detection of orbital angular momentum entangled photon states by hologram shifting method
Miyamoto Yoko; Ozaki Yusuke; Takeuchi Shigeki; Takeda Mitsuo; Sasaki Keiji
The Physical Society of Japan (JPS), 24 Aug. 2012, Meeting abstracts of the Physical Society of Japan, 67, 2, 153-153, Japanese, 1342-8349, 110009601847, AA11439205

Thoughts on the 60th Anniversary of the Optical Society of Japan, JSAP
TAKEDA Mitsuo
10 Apr. 2012, 光学, 41, 4, 182-182, Japanese, 0389-6625, 10030511954, AN00080324

Commemoration of the Founding of the Takano Eiichi Optical Science Funds
TAKEDA Mitsuo
10 Mar. 2012, 光学, 41, 3, 158-159, Japanese, 0389-6625, 10030157480, AN00080324

空間光変調器を用いた干渉計の安定化 II
鳥生太雅; 宮本洋子; 武田光夫; 和田篤
08 Nov. 2010, Optics & Photonics Japan講演予稿集, 2010, 624-625, Japanese, 201102247711059771

Fueki Ryuko : Tradition and New Reform of the Optical Society of Japan
TAKEDA Mitsuo
10 May 2010, 光学, 39, 5, 217-217, Japanese, 0389-6625, 10026198449, AN00080324

白色干渉計測概論 －古くて新しい技術への一つの視点ー
武田 光夫
Mar. 2010, 光アライアンス, 3, Japanese, Invited, Introduction other

グラフィックプロセッサとマルチコアプロセッサの併用によるリアルタイム3次元形状計測
宮本洋子; 和田篤; 飯塚拓郎; 鈴木智也; 中山智章; 青木俊介; 尾崎雄亮; 鳥生太雅; 西野哲朗; 武田光夫
24 Nov. 2009, Optics & Photonics Japan講演予稿集, 2009, 528-529-529, Japanese, 201002236319180202

25aZF-11 Unneeded azimuthal components in detection of orbital angular momentum superposition states II
Miyamoto Yoko; Aoki Shunsuke; Takeuchi Shigeki; Takeda Mitsuo; Sasaki keiji
The Physical Society of Japan (JPS), 18 Aug. 2009, Meeting abstracts of the Physical Society of Japan, 64, 2, 57-57, Japanese, 1342-8349, 110007496168, AA11439205

ホログラムの歪みの補正による異方性の少ないラゲールガウスビームの発生 III
尾崎雄亮; 和田篤; 尾藤浩一; 宮本洋子; 武田光夫
04 Nov. 2008, Optics & Photonics Japan講演予稿集, 2008, 140-141-141, Japanese, 200902234502030763

"Optical Metrology" and "Control of Light" ; "Visible Technology" and "Invisible Technology"
TAKEDA Mitsuo
10 Oct. 2008, 光学, 37, 10, 563-563, Japanese, 0389-6625, 10024339561, AN00080324

22aZA-6 Unneeded azimuthal components in detection of orbital angular momentum superposition states
Miyamoto Yoko; Aoki Shunsuke; Kawase Daisuke; Takeuchi Shigeki; Takeda Mitsuo; Sasaki Keiji
The Physical Society of Japan (JPS), 25 Aug. 2008, Meeting abstracts of the Physical Society of Japan, 63, 2, 124-124, Japanese, 1342-8349, 110006982844, AA11439205

Achromatic interfero-coronagraph with two common-path interferometers in tandem
A. V. Tavrov; J. Nishikawa; M. Tamura; L. Abe; K. Yokochi; T. Kurokawa; M. Takeda; “”; Sep
2008, Applied Optics, 47, 27, 4915, 0003-6935, 80019808785, 18806852

Virtual wavefront compensation and speckle reduction in coronagraph by unbalanced nulling interferometer (UNI) and phase and amplitude correction (PAC)
J. Nishikawa; K. Yokochi; L. Abe; N. Murakami; T. Kotani; M. Tamura; T. Kurokawa; A.V. Tavrov; M. Takeda
2008, Proc. SPIE, Vol. 7010, 70102A

光渦応用計測：ランダム光渦場の位相特異点を用いた新センシング 技術
武田 光夫
日本オプトメカトロニクス協会, 2008, 光技術コンタクト, 46, 6, 253-257, Japanese, Invited, Introduction other, 0913-7289, 40016120833, AN10075091

Detection of orbital angular momentum superposition photon states using hologram and path interferometer
Yoko Miyamoto; Mitsuo Takeda; Daisuke Kawase; Shigeki Takeuchi; Shigeki Takeuchi; Keiji Sasaki; Atsushi Wada
Dec. 2007, Conference on Lasers and Electro-Optics Europe - Technical Digest, Peer-reviwed, 51249094462

23pRH-15 Influence of unneeded azimuthal modes in detection of superposition state of orbital angular momentum
Kawase Daisuke; Takeuchi Shigeki; Aoki Shunsuke; Miyamoto Yoko; Sasaki Keiji; Takeda Mitsuo
The Physical Society of Japan (JPS), 21 Aug. 2007, Meeting abstracts of the Physical Society of Japan, 62, 2, 193-193, Japanese, 1342-8349, 110007143326, AA11439205

Common-path achromatic interferometer-coronagragh: images from a breadboard demonstrator
A. Tavrov; J. Nishikawa; M. Tamaru; L. Abe; K. Yokochi; T. Kurokawa; M. Takeda
2007, Appl. Opt., 46, 28, 6885-6895, 0003-6935, 80018125009, 17906715

ホログラムの歪みの補正による異方性の少ないラゲールガウスビームの発生
尾藤浩一; 和田篤; 米村高志; 青木俊介; 五十嵐早苗; 宮本洋子; 武田光夫
08 Nov. 2006, 日本光学会講演要旨集, 2006, 328-329-329, Japanese, 200902281975862985

26aRB-12 Experimental verification of entanglement in LG modes using path interferometer
Kawase Daisuke; Takeuchi Shigeki; Sasaki Keiji; Wada Atsushi; Miyamoto Yoko; Takeda Mitsuo
The Physical Society of Japan (JPS), 18 Aug. 2006, Meeting abstracts of the Physical Society of Japan, 61, 2, 119-119, Japanese, 1342-8349, 110007178548, AA11439205

26aRB-13 Detection of photon orbital angular momentum superposition states
Miyamoto Yoko; Kawase Daisuke; Takeuchi Shigeki; Wada Atsushi; Takeda Mitsuo; Sasaki Keiji
社団法人日本物理学会, 18 Aug. 2006, Meeting abstracts of the Physical Society of Japan, 61, 2, 120-120, Japanese, 1342-8349, 110007183119, AA11439205

Determining the optical axes of entangled Laguerre Gauss modes
Daisuke Kawase; Shigeki Takeuchi; Keiji Sasaki; Atsushi Wada; Yoko Miyamoto; Mitsuo Takeda
A method for determining the positions of hologram dislocations relative to

the optical axes of entangled Laguerre Gaussian modes is proposed. In our

method, the coincidence count rate distribution was obtained by scanning the

position of one of the holograms in two dimensions. Then, the relative position

of the hologram dislocation was determined quantitatively from the positions of

the minimum and maximum coincidence count rates. The validity of the method was

experimentally verified, and in addition, an experiment demonstrating the

violation of the Clauser-Horne-Shimony-Holt inequality w..., Feb. 2006, Peer-reviwed, Lecture materials

20pWA-5 Phase distribution measurement of Laguerre-Gaussian beam utilizing polarization
Miyamoto Y; Yonemura T; Wada A; Ohminato H; Takeda M
社団法人日本物理学会, 19 Aug. 2005, Meeting abstracts of the Physical Society of Japan, 60, 2, 66-66, Japanese, 1342-8349, 110004537714, AA11439205

プリズム角度と面形状の高精度測定：干渉角度計とその応用
葛宗濤; 齋藤隆行; 大井重徳; 武田光夫
Aug. 2005, 光アライアンス, 16, 5, 49-51, Japanese, Introduction other

27pYE-1 Experimental Study of Statistics of Phase Singularities in Random Light Waves
Wang Wei; Hanson Steen. G.; Miyamoto Yoko; Takeda Mitsuo
The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60, 1, 185-185, English, 1342-8349, 110004534854, AA11439205

Recent developments in spectral interference microscopes (invited)
M. Takeda; D. S. Mehta; M. E. Pawlowski; T. Kurokawa
2005, Eighth International Symposium on Laser Metrology, Proc. of SPIE, Vol. 5776, 22-28

15aTG-12 Verification of measurement basis in entanglement experiments of orbital angular momentum of photons
Kawase Daisuke; Tsujino Kenji; Takeuchi Shigeki; Sasaki Keiji; Wada Atsushi; Ohminato Hiroyuki; Miyamoto Yoko; Takeda Mitsuo
社団法人日本物理学会, 25 Aug. 2004, Meeting abstracts of the Physical Society of Japan, 59, 2, 136-136, Japanese, 1342-8349, 110002051329, AA11439205

30aXG-9 Detection mode analysis for holographic measurement of optical orbital angular momentum
Wada Atushi; Ohminato Hiroyuki; Yonemura Takashi; Miyamoto Yoko; Takeda Mitsuo
社団法人日本物理学会, 03 Mar. 2004, Meeting abstracts of the Physical Society of Japan, 59, 1, 193-193, Japanese, 1342-8349, 110002186707, AA11439205

Reversal of phase singularity and conservation of orbital angular momentum of optical beam with astigmatism
Wada Atushi; Ohminato Hiroyuki; Miyamoto Yoko; Takeda Mitsuo
社団法人日本物理学会, 15 Aug. 2003, Meeting abstracts of the Physical Society of Japan, 58, 2, 123-123, Japanese, 1342-8349, 110002059140, AA11439205

Spectral Interference Mirau Microscope with an Acousto-Optic Tunable Filter for Three-Dimensional Surface Profilometry
共著者; D. S. Mehta; S. Saito; H. Hinosugi; M. Takeda; T. Kurokawa
2003, Applied Optics-OT,, 42, 7, 1296-1305, 0003-6935, 80015804006, 12638886

Spectral Interferometric Microscope with Tandem Liquid-Crystal Fabry-Perot Interferometers for Extension of the Dynamic Range in Three-Dimensional Step-Height Measurement
共著者; D. S. Mehta; H. Hinosugi; S. Saito; M. Takeda; T. Kurokawa; H. Takahashi; M. Ando; M. Shishido; T. Yoshizawa
2003, Applied Optics-OT, 42, 4, 682-690, 0003-6935, 80015748543, 12564487

Frequency-multiplexed profilometric phase coding for three-dimensional object recognition without 2 pi phase ambiguity (vol 27, pg 1466, 2002)
D Choudhury; M Takeda
OPTICAL SOC AMER, Oct. 2002, OPTICS LETTERS, 27, 20, 1851-1851, English, Others, 0146-9592, WOS:000178561300035

Education of Optics and Photonics at Universities
TAKEDA Mitsuo
10 Apr. 2002, 光学, 31, 4, 335-336, Japanese, 0389-6625, 10012333986, AN00080324

ホログラムを用いたラゲールガウスビームの発生
和田篤; 大谷巧; 西原昇; 宮本洋子; 武田光夫
21 Jun. 2001, 光学シンポジウム講演予稿集, 26th, 37-38-38, Japanese, 200902122446402587

Variable Wavelength Interferometer Using Liquid Crystals
KUROKAWA Takashi; TAKEDA Mitsuo
10 Jan. 2001, 光学, 30, 1, 27-28, Japanese, 0389-6625, 10012331325, AN00080324

Generation of Laguerre Gaussian beam by phase hologram III
Miyamoto Y; Wada A; Ohtani T; Masuda M; Takeda M
社団法人日本物理学会, 10 Sep. 2000, Meeting abstracts of the Physical Society of Japan, 55, 2, 99-99, Japanese, 1342-8349, 110002187619, AA11439205

24pA-1 Generation of Laguerre Gaussian beam by phase hologram II
Miyamoto Y; Masuda M; Wada A; Takeda M
社団法人日本物理学会, 03 Sep. 1999, Meeting abstracts of the Physical Society of Japan, 54, 2, 94-94, Japanese, 1342-8349, 110001992685, AA11439205

Multi-dimensional Digital Signal Processing for Three-dimensional Shape Measurements of Objects with Large Height Discontinuities : Temporal Frequency Scan vs. Spatial Frequency Scan
TAKEDA Mitsuo
03 Jun. 1999, 光波センシング技術研究会講演論文集 = Proceedings of ... Meeting on Lightwave Sensing Technology, 23, 9-16, Japanese, 10015810489, AN10547747

光コンピューティング，その多様性と体系化（巻頭言）
武田光夫
Jan. 1999, 光学, 28, 1, 1, Japanese, Introduction other

Generation of Laguerre-Gaussian Beam by Phase Hologram
MASUDA M.; MIYAMOTO Y.; TAKEDA M.
The Physical Society of Japan (JPS), 05 Sep. 1998, Meeting abstracts of the Physical Society of Japan, 53, 2, 334-334, Japanese, 1342-8349, 110002056451, AA11439205

1996 International Topical Meeting on Optical Computing - Preface
J Tanida; T Kurokawa; M Takeda; T Yatagai
OPTICAL SOC JAPAN, Nov. 1996, OPTICAL REVIEW, 3, 6A, U1-U1, English, Others, 1340-6000, WOS:A1996WD97000001

Recent Progress in Optical Computing : A Review of OC'96
TAKEDA Mitsuo
18 Jun. 1996, 光波センシング技術研究会講演論文集 = Proceedings of ... Meeting on Lightwave Sensing Technology, 17, 97-98, Japanese, 10015809668, AN10547747

Vortices in optical ray-vector fields and their influence on the phase unwrapping problem
武田光夫
応用物理学会, 1996, Oyobuturi, 65, 8, 811-816, Japanese, Peer-reviwed, Introduction other, 0369-8009, 10001756270, AN00026679

Fourier fringe analysis and its application : an overview
武田光夫
時間的および(または)空間的に変調ざれた,疑似周期構造をもつしま図形から,被測定物体に関する情報をいかに精度よく取り出すかは,光波,物質波,音波など,波動を利用したすべての計測技術に共通してあらわれる最も基本的な問題である.ここでは,われわれの研究室で開発されたフーリ工変換法とよばれるしま画像解析技術に焦点をあてて,最近の応用分野の発展を紹介し,今後の研究の動向を展望する., The Japan Society of Applied Physics, Jun. 1993, Oyobuturi, 62, 6, 579-583, Japanese, Peer-reviwed, Introduction other, 0369-8009, 10006622599, AN00026679

Optical Interconnection : An overview on passive optical elements and components
武田光夫
1992, IEICE Transactions C-I, J75-C-I, 5, 269-277, Japanese, Peer-reviwed, Introduction other

Optical neurocomputing : A review
武田光夫
1988, Johoshori, 29, 9, 984-992, Japanese, Peer-reviwed, Introduction other

Optical interconnection : A review
武田光夫
VLSI技術による高速・高密度化は,集積回路内部のみならず,コンピューターシステムの各階層における結線量の増大,信号伝搬の遅延,線路の帯域不足などの結線上の問題のために,間もなく限界に近づきつつある.コミュニケーションクライシスと呼ばれるこの障壁を乗う越えるために,光を用いた結線が研究されている.ここでは,高速,広帯域,無誘導,並列性などをはじめ多くの特長をもつ,光インター:ネクションについて,現在提案されている方式を階層別に紹介するとともに,その基礎となる考え方や原理的限界について述べる., The Japan Society of Applied Physics, Mar. 1987, Oyoboturi, 56, 3, 361-367, Japanese, Peer-reviwed, Introduction other, 0369-8009, 130003591977, AN00026679

Highly Sensitive Holography Interferometry by Spatial Carrier-Fringe-Pattern Analysis
Tung Zhi-sin; Takeda Mitsuo
The University of Electro-Communications, 29 Feb. 1984, Reports of the University of Electro-Communications, 34, 2, 231-238, Japanese, 0493-4253, 110000264426, AN00152480

Subfringe interferometry fundamentals : a review
武田光夫
Jan. 1984, Kogaku, 13, 1, 55-65, Japanese, Peer-reviwed, Introduction other, 10008652906

光学技術の辞典
黒田和男; 荒木啓介; 大木裕史; 武田光夫; 森伸芳; 谷田貝豊彦
Joint editor, 朝倉書店, Aug. 2014

Advances in Speckle Metrology and Related Techniques
W. Wang; S. G. Hanson; M. Takeda
English, Joint work, Optical vortex metrology, WILEY -VCH Verlag GmbH, Feb. 2011

光技術総合辞典
武田光夫; 分担執筆
Japanese, Joint work, オプトロニクス社編集部, Dec. 2004

Perspectives in Engineering Optics
M. Takeda; Book C
English, Joint work, Space-time anlalogy in absolute optical profilometry using frequency-scan techniques: A tutorial review, Anita Publications, New Delhi, Apr. 2003

Complex-Valued Neural Networks, Theory and Applications
M. Takeda; T. Kishigami; Book Cha
English, Joint work, Complex neural network model with analogy to self-oscillation generated in an optical phase-conjugate resonator, World Scientific, Pub. Ltd, Singapore, 2003

最新光学技術ハンドブック
辻内順平; 黒田和男; 大木裕; 河田聡; 小島忠; 武田光夫; 南節雄; 谷田貝豊彦
Japanese, Editor, 朝倉書店, Sep. 2002

応用物理学会編「応用物理用語大辞典」
武田光夫
Japanese, Joint work, オーム社, 1998

光サイエンス辞典
武田光夫
Dictionary or encycropedia, Japanese, オプトロニクス社, 1998

Handbook of Optical Computing
武田光夫
Japanese, Joint work, Asakura Shoten Pub. Co. , Tokyo, 1997

Fundamentals and New Application of Liquid Crystal Devices
武田光夫
Japanese, Joint work, Sigma Pub. Co. , Tokyo, 1997

Dictionary of optoelecronics
武田光夫
Japanese, Joint work, Ohmsha Pub. Co. , Tokyo, 1996

Statistical Optics
武田光夫
Japanese, Editor, Maruzen Pub. Co. , Tokyo, 1992

Optical Computing in Japan
M. Takeda; Book C
English, Joint work, Nava Science Pub. Inc. , New York, 1990

Neurocomputer
武田光夫
Japanese, Joint work, Science Forum Pub., 1989

Handbook of Optoelecronics
武田光夫
Japanese, Joint work, Shokodo Pub. Co. , Tokyo, 1988

Handbook of Optical Engineering
武田光夫
Japanese, Joint work, Asakura Shoten Pub. Co. , Tokyo, 1986

Dictionary of physics
武田光夫
Japanese, Joint work, Baifukan Pub. Co. , Tokyo, 1984

Measurement of extreme physical phenomena by Fourier fringe analysis
M. Takeda
Keynote oral presentation, English, ICO-22, 22nd General Congress of the International Commission for Optics, ICO-22, 22nd General Congress of the International Commission for Optics, Puebla, Mexico, International conference
Aug. 2011

Coherence holography: Principle and Applications
M. Takeda
Keynote oral presentation, English, SPIE Optical Metrology, SPIE Optical Metrology, Munich, Germany, International conference
May 2011

Coherence Holography: A Tutorial Review
M. Takeda
Invited oral presentation, English, OSA Topical Meeting on Digital Holography and Three-Dimensional Imaging (DH), OSA Topical Meeting on Digital Holography and Three-Dimensional Imaging (DH), Tokyo, Japan, International conference
May 2011

非対称ナル干渉法と高コントラスト撮像法
西川淳; 田村元秀; 横地界斗; 黒川隆志; 村上尚史; L. Abe; 小谷隆行; 村上浩志; A. Tavrov; 武田光夫
Oral presentation, Japanese, 第11回 宇宙科学シンポジウム,第11回 宇宙科学シンポジウム
Jan. 2011

Coherence Holography: Principle and Applications
M. Takeda; W. Wang; D. N. Naik; Y. Miyamoto
Keynote oral presentation, English, Optical Society of India, International Conference on Contemporary Trends in Optics and Opto Electronics, Optical Society of India, International Conference on Contemporary Trends in Optics and Opto Electronics, Thiruvananthapuram, India, International conference
Jan. 2011

Polarization speckles and generalized Stokes vector wave: a review
M. Takeda; W. Wang; S. G. Hanson
Invited oral presentation, English, Speckle 2010, Speckle 2010, Florianopolis, Brazil, International conference
Sep. 2010

Utilizing the coherence properties of light for optical metrology
M. Takeda
Invited oral presentation, English, HoloMet 2010 3rd International Workshop on Perspectives of Optical Imaging and Metrology, HoloMet 2010 3rd International Workshop on Perspectives of Optical Imaging and Metrology, Balatonfuered, Hungary, International conference
Jun. 2010

Measurements of extreme physical phenomena by Fourier fringe analysis
M. Takeda
Invited oral presentation, English, International Conference on Adavanced Phase Measurement Methods in Optics and Imaging, AIP, Ascona, Switzerland, International conference
May 2010

Vector correlation for polarization speckle and its application to optical metrology
W. Wang; S.G. Hanson; M. Takeda
Invited oral presentation, English, The Ninth International Conference“Correlation Optics 2009", European Physical Society, Chernivtsi, Ukraine, International conference
Sep. 2009

Propagation of the polarization coherence matrix through complex ABCD-optical systems
S.G. Hanson; W. Wang; D. N. Naik; M. Takeda
Invited oral presentation, English, The Ninth International Conference“Correlation Optics 2009”, European Physical Society, Chernivtsi, Ukraine, International conference
Sep. 2009

Coherence holography: A thought on synthesis and analysis of optical coherence field
M. Takeda; W. Wang; D. N. Naik
Invited oral presentation, English, 6th International Workshop on Advanced Optical Metrology, Fringe 2009, Univ. of Stuttgart, Stuttgart, Germany, International conference
Sep. 2009

Development of Fourier-fringe analysis and its applications in extreme optical metrology
M. Takeda
Keynote oral presentation, English, Eighth Japan-Finland Joint Symposium on Optics in Engineering, OIE 09, NGPA, Tokyo Univ of Science, Optical Society of Japan, Tokyo, Japan, International conference
Sep. 2009

Optical Vortex Metrology
M. Takeda; W. Wang; S. G. Hanson; Y. Miyamoto
Invited oral presentation, English, The 9th International Symposium on Measurement Technology and Intelligent Instruments, International Committee on Measurements and Instrumentation, Russian Academy of Sciences, St. Petersburg, Russia, International conference
Jun. 2009

Optical vortex metrology: Displacement and flow measurements with phase singularities
M. Takeda; W. Wang; S. G. Hansaon
Invited oral presentation, English, Japan Taiwan Bilateral Science and Technology Symposium, Frontiers in Functional Optics, Japan Taiwan Bilateral Science and Technology Symposium, Frontiers in Functional Optics, Utsunomiya, Japan, International conference
Nov. 2008

Coherence dynamics, coherence topology, and singular optical coherence
W. Wang; M. Takeda
Invited oral presentation, English, International Topical Meeting on Information Photonics 2008, International Topical Meeting on Information Photonics 2008, Awaji, Japan, International conference
Nov. 2008

Coherence holography and spatial frequency comb for 3-D coherence imaging and coherence vortex generation
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto; J. Rosen
Invited oral presentation, English, Best of Topicals in Frontiers in Optics (FiO)/Laser Science XXIV (LS) Conference, Best of Topicals in Frontiers in Optics (FiO)/Laser Science XXIV (LS) Conference, OSA, Rochester, USA, International conference
Oct. 2008

Coherence holography and time-space analogy in coherence functions
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Keynote oral presentation, English, International Symposium to Commemorate the 60th Anniversary of the Invention of Holography, Proc. International Symposium to Commemorate the 60th Anniversary of the Invention of Holography, Springfield, USA), International conference
Oct. 2008

Experimental investigation of the singular phenomena in statistical optical fields
W. Wang; M. Takeda
Invited oral presentation, English, The Nature of Light: Light in Nature II, SPIE, The Nature of Light: Light in Nature II, San Diego, USA, International conference
Aug. 2008

Coherence holography and singular optical coherence
M. Takeda; W. Wang
Invited oral presentation, English, Optics and Photonics for Information Processing II, Optics and Photonics for Information Processing II, Proc. of SPIE, San Diego, USA, International conference
Aug. 2008

Coherence holography and 3-D coherence synthesis for dispersion-free spatial frequency tomography and profilometery
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Invited oral presentation, English, Photon 08, Photon 08, IOP, Edinburgh, UK, International conference
Aug. 2008

Coherence Holography and Spatial Frequency Comb for 3-D Coherence Imaging
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto; J. Rosen
Invited oral presentation, English, OSA Topical Meeting on Digital Holography, OSA Topical Meeting on Digital Holography, St. Petersburg, USA, International conference
Mar. 2008

位相特異点のポアンカレ球表現とその流体運動解析への応用
石島玲華; W. Wang; 横関友亮; 松田充弘; M. R. Dennis; S. G. Hanson; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

単一分光帯域インターフェログラムの位相ゼロクロス情報を用いた白色干渉計測法
木村高啓; M. Pawlowski; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007
Nov. 2007

コヒーレンスホログラフィーにより生成された３次元空間コヒーレンス関数の新検出法
韋冬; 宮本洋子; 武田 光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

幾何学的位相によるナル干渉計の波長無依存性
横地界斗; A. Tavrov; 西川 淳; L. Abe; 田村元秀; 武田光夫; 黒川隆志
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

偏光スペックルのストークスベクトル相関
松田充弘; W. Wang; S. G. Hanson; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

ホログラムの歪みの補正による異方性の少ないラゲールガウスビームの発生II
尾藤浩一; 尾崎雄亮; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

軌道コヒーレンス角運動量とコヒーレンス関数の波と粒子の双対性
W. Wang; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

コヒーレンス角運動量のスピンと軌道角運動量への分解
W. Wang; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

コヒーレンス渦場のフラクショナルトポロジカルチャージ
W. Wang; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

偏光の特異点の生成と検出
五十嵐早苗; 米村高志; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

ホログラムで発生させたドーナツビームの異方性の定量評価
尾崎雄亮; 和田篤; 尾藤 浩一; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

光子の軌道角運動量重ね合わせ状態検出における余分な方位角成分の影響
青木俊介; 宮本洋子; 川瀬大輔; 竹内繁樹; 武田光夫; 笹木敬司
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

スペックル状パターンの複素信号表現による擬似ストークスベクトル相関法
石島玲華; W. Wang; 松田充弘; S. G. Hanson; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photonics Japan 2007 講演予稿集,日本光学会 Optics and Photonics Japan 2007 講演予稿集
Nov. 2007

Optical vortex metrology: Are phase singularities foes or friends in optical metrology?
M. Takeda; W. Wang; S. G. Hanson; Y. Miyamoto
Keynote oral presentation, English, 8th International Conference on Correlation Optics, 8th International Conference on Correlation Optics (Chernivtsi, Ukraine), Chernivtsi, Ukraine, International conference
Sep. 2007

Coherence vortices, coherence current, and the conservation laws in coherence dynamics
W. Wang; S. G. Hanson; M. Takeda
Invited oral presentation, English, 8th International Conference on Correlation Optics, 8th International Conference on Correlation Optics (Chernivtsi, Ukraine), Chernivtsi, Ukraine, International conference
Sep. 2007

Optical vortex metrology: Displacement measurements with phase singularities
M.Takeda; W. Wang; S. G. Hanson; Y. Miyamoto
Invited oral presentation, English, Sixth Euro-American Workshop on Information Optics, Sixth Euro-American Workshop on Information Optics (AIP), Reykjavik, Iceland, International conference
Jul. 2007

Optical Vortex Metrology: A new optical sensing technique using phase singularities in random optical vortex fields
M. Takeda
Invited oral presentation, Japanese, 日本光学会第32回光学シンポジウム, Proc. 32nd Optics Simposium
Jul. 2007

Coherence holography: Priniciple and applications
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Invited oral presentation, English, Workshop on Random Electromagnetic Fields, Workshop on Random Electromagnetic Fields, Orland, USA, International conference
May 2007

非対称ナル干渉と補償光学を融合した系外惑星直接検出のための超高コントラスト撮像法(2)
西川淳; Lyu Abe; 村上尚史; A. Tavrov; 田村元秀; 小谷隆行; 横地界斗; 黒川隆志; 武田光夫
Oral presentation, Japanese, 日本天文学会2007年秋季年会,日本天文学会2007年秋季年会
2007

Coherence Holography and Spatial Frequency Comb: Control and Synthesis of Spatial Coherence Function for Dispersion-free Photonic Sensing
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Keynote oral presentation, English, 8th International Conference on Optoelectronics, Fiber Optics and Photonics, Photonics 2006, 8th International Conference on Optoelectronics, Fiber Optics and Photonics, Photonics 2006, Hyderabad, India, International conference
Dec. 2006

解析信号表現されたランダムパターンの位相特異点の空間構造を利用した光計測とその生物学的運動解析への応用
石島玲華; W. Wang; Y. Qiao; 横関友亮; 本多大吾; 松田充弘; S. G. Hanson; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photinics Japan 2006 講演予稿集,日本光学会 Optics and Photinics Japan 2006 講演予稿集
Nov. 2006

Rotational coherence current and the origin of coherence vortex," Extended Abstracts
W. Wang; M. Takeda
Oral presentation, English, OSJ, Optics and Photonics Japan 2006
Nov. 2006

光渦計測法によるスペックル変位および変形計測
石島玲華; W. Wang; 横関友亮; S. G. Hanson; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photinics Japan 2006 講演予稿集,日本光学会 Optics and Photinics Japan 2006 講演予稿集
Nov. 2006

ホログラムの歪みの補正による異方性の少ないラゲールガウスビームの発生
尾藤浩一; 和田篤; 米村高志; 青木俊介; 五十嵐早苗; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photinics Japan 2006 講演予稿集,日本光学会 Optics and Photinics Japan 2006 講演予稿集
Nov. 2006

Complex amplitude correlation of dynamic speckle and its application to speckle metrology
W. Wang; S. G. Hanson; M. Takeda
Oral presentation, English, Extended Abstracts, Optics and Photonics Japan 2006
Nov. 2006

Arbitrarily shaping of coherence function: A new optical design in coherence domain
W. Wang; Z. Duan; S. G. Hanson; M. Takeda
Oral presentation, English, Extended Abstracts, Optics and Photonics Japan 2006
Nov. 2006

非対称ナル干渉計と波面補償による系外惑星直接検出のための超高ダイナミックレンジ光学系
西川淳; 村上尚史; Abe Lyu; 小谷隆行; 田村元秀; 横地界斗; 黒川隆志; A. Tavrov; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics and Photinics Japan 2006 講演予稿集,日本光学会 Optics and Photinics Japan 2006 講演予稿集
Nov. 2006

Common-path achromatic nulling interferometer for star coronagraphy: demonstrator and images on breadboard
A. Tavrov; K. Yokochi; J. Nishikawa; M. Tamura; T. Kurokawa; M. Takeda
Oral presentation, English, Extended Abstracts, Optics and Photonics Japan 2006
Nov. 2006

Coherence Holography: Principle and Applications
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Invited oral presentation, English, Speckle06: Speckles, from Grains to Flowers, Proc. SPIE, Speckle06: Speckles, from Grains to Flowers, Nimes, France, International conference
Sep. 2006

コヒーレンスホログラフィー：コヒーレンス場を生成・制御する新ホログラフィー技術
武田光夫
Invited oral presentation, Japanese, 第53回応用物理学関係連合講演会講演予稿集No.0, 第53回応用物理学関係連合講演会講演予稿集No.0
Mar. 2006

Coherece holography for 3-D coherence synthesis: Yet another approach to dispersion-free optical coherence tomography and profilometry
M. Takeda
Invited oral presentation, English, Symposium on Molecular Imaging: Biomedical Photonics in 21st Century, Symposium on Molecular Imaging: Biomedical Photonics in 21st Century, Tokyo, Japan, International conference
Mar. 2006

ベリー位相を利用した太陽系外惑星検出用干渉計
武田光夫
Others, Japanese, 日本学術振興会光エレクトロニクス第130委員会第246回研究会資料, 日本学術振興会光エレクトロニクス第130委員会第246回研究会資料
Dec. 2005

ラゲールガウスビーム発生用ホログラムの歪みによるビームの変形
和田篤; 大湊博之; 米村高志; 尾藤浩一; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会Optics Japan 2005 講演予稿集,Optics Japan 2005 講演予稿集
Nov. 2005

空間コヒーレンス関数の3次元分布の直接可視
Wei Wang; Zhihui Duan; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2005 講演予稿集,日本光学会 Optics Japan 2005 講演予稿集
Nov. 2005

空間周波数可制御光源を用いた絶対干渉計測法
段志輝; 韋冬; 山田明紀; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2005 講演予稿集,日本光学会 Optics Japan 2005 講演予稿集
Nov. 2005

液晶波長可変フィルタを用いた正弦波状波長走査フィードバック干渉計による実時間距離測定
佐々木修己; 斎藤昭洋; 鈴木孝昌; 武田光夫; 黒川隆志
Oral presentation, Japanese, 日本光学会 Optics Japan 2005 講演予稿集,日本光学会 Optics Japan 2005 講演予稿集
Nov. 2005

空間コヒーレンス関数の位相特異点の局所構造
Wei Wang; 段志輝; Steen G. Hanson; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2005 講演予稿集,日本光学会 Optics Japan 2005 講演予稿集
Nov. 2005

偏光を利用する位相測定法を用いたラゲールガウスビームの位相分布測定II
米村高志; 和田篤; 尾藤浩一; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2005 講演予稿集,日本光学会 Optics Japan 2005 講演予稿集
Nov. 2005

スペックルパターンのRiesz変換解析信号の位相特異点を用いたナノ変位計測
横関友亮; Wei Wang; 石島玲華; 和田篤; Steen Hanson; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2005 講演予稿集,日本光学会 Optics Japan 2005 講演予稿集
Nov. 2005

Recent developments in spectral interference microscope for surface profilometry and tomography of discontinuous micro objects
M. Takeda; D. S. Mehta; T. Kurokawa
Invited oral presentation, English, Nanoengineering Symposium 2005, Nanoengineering Symposium 2005, Daejeon, Korea, International conference
Oct. 2005

EUVA's challenges toward 0.1nm accuracy in EUV at-wavelength interferometry
K. Sugisaki; M. Hasegawa; M. Okada; Y. Zhu; K. Otaki; Z. Liu; M. Ishii; J. Kawakami; K. Murakami; J. Saito; S. Kato; C. Ouchi; A. Ohkubo; Y. Sekine; T. Hasegawa; A. Suzuki; M. Niibe; M. Takeda
Invited oral presentation, English, Fringe’05: International Workshop on Automatic Processing of Fringe Patterns, Fringe’05: International Workshop on Automatic Processing of Fringe Patterns, Stuttgart, Germany, International conference
Sep. 2005

Coherence holography and 3-D coherence synthesis for optical tomography and profilometry
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Invited oral presentation, English, Sixth Japan-Finland Joint Symposium on Optics in Engineering, Sixth Japan-Finland Joint Symposium on Optics in Engineering, Sapporo, Japan, International conference
Sep. 2005

Coherence holography: Holographic imaging with coherence function
M. Takeda; W. Wang; Z. Duan; Y. Miyamoto
Invited oral presentation, English, Holography 2005, International Conference on Holography, Optical Recording, and Processing of Information, Bulgarian Academy of Science, Varna, Bulgaria, International conference
May 2005

Recent developments in spectral interference microscopes
M. Takeda; D. S. Mehta; M. E. Pawlowski; T. Kurokawa
Invited oral presentation, English, 8th International Symposium on Laser Metrology, Proc. SPIE, 8th International Symposium on Laser Metrology, Merida, Mexico, International conference
Feb. 2005

Achormatic out-of-plane common-path interferometer: nulling of polychromatic light
A. Tavrov; T. Kurokawa; M. Takeda
Others, English, TUAT/UEC, The 21st Century COE Joint Symposium, Technical Digest
Dec. 2004

Pseudo-phase information of complex analytic signal of speckle fields and its applications: Micro-displacement measurement based on phase-only correlation in signal domain
W. Wang; N. Ishii; Y. Miyamoto; M. Takeda
Others, English, TUAT/UEC, The 21st Century COE Joint Symposium, Technical Digest
Dec. 2004

非点収差による光の位相特異点の反転と軌道角運動量の保存
和田篤; 大湊寛之; 米村高志; 宮本洋子; 武田光夫
Others, Japanese, 東京農工大・電通大21世紀ＣＯＥプログラム合同シンポジウム予稿集「ナノ未来材料とコヒーレント光科学」予稿集
Dec. 2004

ラゲールガウスビームを用いた光トラップとトラップ力の評価
大湊寛之; 和田篤; 米村高志; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2004 講演予稿集
Nov. 2004

白色干渉縞解析法の特性比較(II)
坂野洋平; M. Pawlowski; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2004 講演予稿集
Nov. 2004

非散乱性表面を持つ鏡面状物体の３次元形状計測
横関友亮; 廣岡成一; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2004 講演予稿集
Nov. 2004

偏光を利用した位相測定法を用いたラゲールガウスビームの位相分布測定
米村高志; 和田篤; 大湊寛之; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2004 講演予稿集
Nov. 2004

Statistical properties of analytic signal of white-light speckle pattern and its application to in-plane displacement
W. Wang; N. Ishii; Y. Miyamoto; M. Takeda
Oral presentation, English, Extended Abstracts, Optics Japan 2004
Nov. 2004

Spatio-spectral interferometry with adaptive numerical refocusing
M. Pawlowski; Y. Sakano; Y. Miyamoto; M. Takeda
Oral presentation, English, Extended Abstracts, Optics Japan 2004
Nov. 2004

ホログラムを用いて発生させたドーナツビームのモード解析
和田篤; 大湊寛之; 米村高志; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2004 講演予稿集
Nov. 2004

Theory and principle of three-dimensional shape measurements: From macroscopic to microscopic objects
M. Takeda
Invited oral presentation, English, Proc. Joint Japan-Tunisia Workshop on Computer Systems and Information Technology, JT-CSIT'04, Proc. Joint Japan-Tunisia Workshop on Computer Systems and Information Technology, JT-CSIT'04, Tokyo, Japan, International conference
Jul. 2004

Space-time analogy in synthetic coherence functions applied to optical tomography and profilometry
M. Takeda; J. Rosen; D. Zhihui
Keynote oral presentation, English, Proceedings of International Conference on Laser Applications and Optical Metrology, New Delhi, India, International conference
Dec. 2003

非点収差を与えたラゲールガウスビームの伝播過程の解析II
和田篤; 大湊寛之; 米村高志; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2003 講演予稿集
Dec. 2003

ホログラムを用いた光ビームの位相特異点の操作
大湊寛之; 和田篤; 米村高志; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2003 講演予稿集
Dec. 2003

白色干渉縞の縞解析法の比較：包絡線の最大値検出 vs. 分光位相勾配検出
坂野洋平; 仙場淳; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2003 講演予稿集
Dec. 2003

スッペックル場の複素解析信号の擬似位相情報とその応用(I)：位相特異点を用いた微小変位計測
石井信生; Wang Wei; 宮本洋子; 服部修二; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2003 講演予稿集
Dec. 2003

スッペックル場の複素解析信号の擬似位相情報とその応用(II)：信号領域で振幅を同一化した位相相関法による微小変位計測
Wang Wei; 石井信生; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2003 講演予稿集
Dec. 2003

空間周波数走査とフーリエ縞解析による不連続物体の3次元形状計測
巻幡智明; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan 2003 講演予稿集
Dec. 2003

SSG-DBRレーザーを用いた高速・高分解能OFDR-OCT
崔東学; 天野卓治; 廣岡秀明; 武田光夫; 清水公也; 大林康二
Oral presentation, Japanese, 日本光学会光学シンポジウム講演番号13
Jun. 2003

Absolute 3-D sensor with single fringe-pattern recording
Y. Kasai; Y. Miyamoto; M. Takeda; H. Tanaka; R. Gu
Keynote oral presentation, English, 7th International Symposium on Laser Metrology Applied to Science, Industry, and Everyday Life, Proc. SPIE, Russian Academy of Science, Novosibirsk, Russia, International conference
Sep. 2002

Absolute 3-D sensor with single fringe-pattern recording
Y. Kasai; Y. Miyamoto; M. Takeda; H. Tanaka; R. Gu
Invited oral presentation, English, 7th International Symposium on Laser Metrology Applied to Science, Industry, and Everyday Life, Proc. SPIE, International conference
Sep. 2002

Theory and principle of three-dimensional shape measurements: from macroscopic to microscopic objects
M. Takeda
Invited oral presentation, English, Technical Digest of The Rank Prize Funds Mini-symposium on Optical Metrology Techniques for Industrial Applications, The Rank Prize Funds, Loughborough, UK, International conference
Apr. 2002

Theory and principle of three-dimensional shape measurements: from macroscopic to microscopic objects
M. Takeda
Invited oral presentation, English, Technical Digest of The Rank Prize Funds Mini-symposium on Optical Metrology Techniques for Industrial Applications, International conference
Apr. 2002

Evolution of Optical Vortices and Phase Singularities in Scattered Random Fields: -Experimental Observation of Their 3-D Structures-
T. Sotomaru; H. Tsuchiya; Y. Miyamoto; M. Takeda
Invited oral presentation, English, International Balatonfuered Workshop on New Prospectives for Optical Metrology, HoloMet 2001 (Baratonfuered, Hungary), International conference
Jun. 2001

Multidimensional fringe pattern analysis: Technique and Analysis
M. Takeda
Keynote oral presentation, English, Conference Handbook, Applied Optics and Opt-Electronics Conference, Institute of Physics（Loughborough, UK）（Invited Plenary Paper）, International conference
Sep. 2000

Fourier transform profilometry
M. Takeda
Invited oral presentation, English, Trends in Optical Nondestructive Testing and Inspection（P. K. Rastogi and D. Inaudi, Eds）Elsevier,（Invited Paper）, International conference
May 2000

Holographic generation of a Laguerre-Gaussian beam with higher-order phase singularity
M. Masuda; A. Wada; T. Ohtani; Y. Miyamoto; M. Takeda
Invited oral presentation, English, International Berlin Workshop on New Prospects of Holography and 3-D Metrology（Invited Paper）, International conference
May 2000

ラゲールガウスビーム発生のための位相ホログラム素子の作成（II）
和田篤; 増田満俊; 大谷巧; 宮本洋子; 武田光夫
Oral presentation, Japanese, 日本光学会 Optics Japan '99 講演予稿集
Nov. 1999

A method to evaluate the geometrical spin-redirection phase for nonplanar ray
A. V. Tavrov; Y. Miyamoto; T.Kawabata; M. Takeda; V. V. Andree
Oral presentation, English, Extended Abstracts, Optics Japan '98
Sep. 1998

The Optical Society of America

SPIE (The International Society for Optical Engineering)

Japan Society of Applied Physics

The Optical Society of Japan

Basic research for the creation of "Spatial Statistical Optics"
Takeda Mitsuo; HANSON Steen, G.; WANG Wei; NAIK Dinesh, N.
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Utsunomiya University, Grant-in-Aid for Scientific Research (C), Noting the symmetry between space and time variables in the wave equation, a new realm of statistical optics, called spatial statistical optics, has been created in which the ensemble average is replaced by the spatial average, rather than by the time average in conventional statistical optics. The following results have been achieved. (1) The conditions on a source and an optical system have been clarified for the statistical field to have wide-sense spatial stationarity. (2) The theory and the method of experiment have been proposed for spatial statistical analysis of vectorial optical fields. (3) The methods for generation of polarization speckle fields with a birefringent scatter plate and their spatial statistical analysis have been proposed. (4) New imaging techniques have been proposed that are based on spatial statistical optics., 25390090
01 Apr. 2013 - 31 Mar. 2017

Very high dynamic range optics for direct detection of extra-solar planets
NISHIKAWA Jun; KUROKAWA Takashi; TAKEDA Mitsuo; TAMURA Motohide
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, National Astronomical Observatory of Japan, Grant-in-Aid for Scientific Research (B), We studied an unbalanced nulling interferometer(UNI), adaptive optics, and coronagraphs in order to obtain a very high dynamic range optics for direct detection of extra-solar planets. Aλ/600 rms wavefront correction was made virtually when the accuracy of the adaptive optics wasλ/100 rms thanks to the effect of the UNI, and a noise level of the focal image of the coronagraph was suppressed by more than one order of magnitude. An eight-octant phase mask showed a contrast of 2E-8 with a bandwidth of 10%. A four-quadrant phase mask was shown to function as a stable UNI., 21360037
2009 - 2011

Polarization coherence synthesizer : Singular optics of generalized Stokes fields with application to optical metrology
TAKEDA Mitsuo; MIYAMOTO Yoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), A basic principle of a polarization-coherence synthesizer was proposed, and foundation was laid for the technique that can control both polarization and spatial coherence of statistical 3-D vectorial optical fields simultaneously. A novel scheme of coherence holography was devised for controlling the elements of a polarization-coherence matrix of a vectorial optical field. A technique, called Stokes holography, that reconstructs a desired image as a 3-D distribution of generalized Stokes parameters was proposed and experimentally demonstrated., 21360028
2009 - 2011

A study of high dynamic range optics with nulling interferometer and adaptive optics
NISHIKAWA Jun; KUROKAWA Takashi; TAKEDA Mitsuo; TAMURA Motohide; MURAKAMI Naoshi; KUROKAWA Takashi; TAKEDA Mitsuo; TAMURA Motohide
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, National Astronomical Observatory of Japan, Grant-in-Aid for Scientific Research (B), 太陽系以外の惑星を直接検出する高ダイナミックレンジ光学系として、波面誤差補正によるスペックルノイズ除去と惑星よりきわめて強い恒星の回折光の除去を交互に2回ずつ行う、初段補償光学、非対称ナル干渉計、位相振幅補正補償光学、コロナグラフ、からなる4 段階複合法を研究した。非対称ナル干渉計の波面誤差拡大効果で実質的に補償光学の限界を超えた波面精度を達成し、コロナグラフで広帯域の回折光の除去などを実証した。, 19360036
2007 - 2008

Coherence holography : Fundamentals and applications of an unconventional holographic technique for synthesis and control of coherence fields
TAKEDA Mitsuo; MIYAMOTO Yoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), 3次元物体をランダムな光波動場の空間コヒーレンス関数として再生するコヒーレンスホログラフィーの新原理を提案し,実験によりその有効性を実証した.コヒーレンスホログラムを計算機合成することにより,3次元空間コヒーレンス関数を自由に制御・シンセシスする技術を実現した.この新機能を用いた新しい工学的応用として波長分散のない3次元形状計測の可能性を実証した.また,基礎科学面ではコヒーレンス関数に位相特異点をもつコヒーレンス渦場を生成し,コヒーレンス場の運動量や角運動量などコヒーレンス場の力学的性質を解明した., 18360034
2006 - 2008

太陽系外地球型惑星の直接検出のための超高コントラスト装置の開発
村上 尚史; 武田 光夫
日本学術振興会, 科学研究費助成事業, 国立天文台, 特定領域研究, 我々は,太陽系外惑星を直接撮像するため,非対称ナル干渉計(Unbalanced Nulling Interferometer,UNI)および補償光学系(Phase-AmplitudeCorrection,PAC)を用いた超高コントラスト装置(通称,UNI-PAC法)を提案し,検証実験を行った。系外惑星の直接撮像を行うためには,明るい恒星からのスペックルノイズを10^<-10>レベルにまで減らすため,λ/10000rmsもの超高面精度の光学素子や光波面補正が必要とされる。提案する手法は,UNIによる光波面誤差の拡大とPACによる波面補正を行い,更に後置コロナグラフを用いることにより,上記のような高面精度のオプティクスを必要としないという,画期的な手法である。 平成19年度は,UNI部の安定・高性能化を目指した光学系の改修,およびPAC部の構築を行った。具体的には,ナル干渉計の振動抑制のための光学素子マウント製作,傾斜補正鏡の導入,可変形鏡および波面センサ部のマウント製作を行った。その結果,ナル干渉計単体で恒星モデル像のスペックルノイズを,5λ/D以遠で10^<-7>オーダーにまで抑制させることに成功した。また、UNIによる波面誤差拡大の観測に成功し,拡大率がほぼ理論的予測と一致することを確認した。また,後置コロナグラフとして3Dサニャックナル干渉計を導入し,提案する装置全体の検証実験を行った。その結果,3Dサニャックナル干渉計単体と比較して高いコントラストを達成することができた。 更に,後置コロナグラフとして,像面位相マスクコロナグラフの使用も検討した。特に,従来提案されている4分割位相マスクを多分割化(8分割)にすることにより,更に効率的に恒星光除去が行えることを,数値シミュレーションおよび検証実験により明らかにした。, 19015009
2007 - 2007

幾何学的位相を利用した立体サニャック干渉光学計の研究
黒川 隆志; 武田 光夫
日本学術振興会, 科学研究費助成事業, 東京農工大学, 萌芽研究, 現在までに約260個の太陽系外の惑星(系外惑星と呼ぶ)が発見されているが,そのほとんどは,恒星の測光などの間接的な観測によるものである.現在,系外惑星からの光を直接観測し,特に地球型惑星のスペクトル中に生命の痕跡である酸素の有無を調べることが現代天文学の最大の課題の1つとなっている. 本研究では,コロナグラフとして幾何学的位相変調を用いた3次元サニャックナル干渉計の性能評価実験を行った.緑と赤(532nmと632.8[nm])の2波長のレーザーを同時にナル干渉させ,3次元サニャック干渉計の波長無依存性を検証する実験を行った.像面では,強め合う干渉のピークと弱め合う干渉のピークで,赤色レーザでは8.43×10^<-5>,緑色レーザでは3.15×10^<-5>となり,波長に依存しないナル干渉を確認した。また,瞳面全体での消光比の平均は,赤色レーザで4.88×10^<-4>,緑色レーザで3.42×10^<-4>となり,20%に近い比帯域でアクロマティック性を証明した.これにより,本手法の波長無依存性を実証することができた. 像面,瞳面ともほぼ同様の結果が得られたが,緑色レーザと赤色レーザでの干渉パターンが異なっている.原因としては,系全体のドリフト,ビームスプリッタでの分散などが考えられる., 18656018
2006 - 2007

3D microscopy based on optical frequency comb by RF control
KUROKAWA Takashi; SHIODA Tatsutoshi; TAKEDA Mitsuo
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Tokyo University of Agriculture and Technology, Grant-in-Aid for Scientific Research (B), In our previous report, the optical frequency comb generator consisting of two phase modulators in tandem we used generated the narrow bandwidth of the comb spectrum, only 2 nm, and resulted in the limited resolution up to 300μm. And some noises of many side-lobes appeared around the interferometric peaks due to a rectangular frequency comb spectrum. Furthermore, it took a long time for the data acquisition because the point-to-point scanning was used in a fiber-optic interferometer. To improve the performance of our previous system, we introduced new functions of a broad band frequency comb and a line-type image sensor to realize a frequency comb-based interferometric microscope. One of the improvements in the proposed system is that a broadband frequency comb spectrum of over 10 nm was obtained by combining a waveguide type-frequency comb generator^<6-8)> consisting of the phase modulator installed in the Fabry-Perot cavity and a subsequent wavelength equalizer^<9)>. The depth resolution is finally improved up to 35 μm, and the side-lobes in the interferometric signals also disappeared. Another important improvement is to realize a high-speed observation of three-dimensional images by the use of a line type-image sensor for capturing a line image in a horizontal direction at a time. The measurement resolution narrowed finally to 35 μm by introducing the waveguide-type frequency comb generator and the wavelength equalizer. Furthermore, introducing the line image sensor can obtain the simultaneous measurement of the whole horizontal cross sectional image of the interferometric signal. We successfully demonstrated the 3 dimensional surface profilometry of a Japanese 10-yen coin and observation of a cross sectional tomography image of transparent thin films by varying the comb frequency interval without mechanical shift. The dynamic range in the depth direction was about 1.1 mm and the measurement resolution was 35μm. The standard deviation of seven times thickness measurements was 5μm., 18360164
2006 - 2007

Investigation of the quantum reflection of atoms on a solid state surface
SHIMIZU Kazuko; TAKEDA Mitsuo; MORINAGA Makoto
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, University of Electro-Communications, Grant-in-Aid for Scientific Research (B), We studied the quantum reflection of the metastable helium atoms on a flat polished silicon surface. We measured the reflectivity as a function of the normal incident velocity component between 3 and 30 cm/s, and confirm that on a flat surface the reflection of atoms is caused by the attractive van der Waals potential. In our case the atoms are mainly reflected in a region where the retardation effect leads to a potential of the approximate form, U(z)=-C_4/z^4 where z is the distance from the surface. We also studied the reflection and diffraction on surface structures consisting of parallel narrow ridges. The structure consists of wall-like ridges at a distance of L=5μm and with a width at the top of l=100nm. We observed on this structure an increase of the reflectivity by two orders of magnitude, exceeding 10% for normal incident velocities below about 25cm/s. At grazing incidence even fast atoms of 100m/s can be reflected very efficiently at such a surface structure. In order to quantitatively describe our data, we have developed a theoretical description of the reflection and scattering of atomic waves from our surface structures. As a first approximation we can assume that the van der Waals constant is reduced by a factor l/L, where l is the size at the top of the ridges and L the distance between the ridges. The reflectivity on the ridges structures then follows immediately from the scaling law of the quantum reflection. Deviations appear when the ratio l/L is very small. In the limiting case of l/L→0, i.e. of idealized thin ridges, a new interesting effect can be observed: The atomic wave is reflected due to the Fresnel diffraction at the array of ridges., 16340116
2004 - 2006

Study of coherence tomography based on optical frequency comb
KUROKAWA Takashi; TANAKA Yosuke; SHIODA Tatsutoshi; TAKEDA Mitsuo
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Tokyo University of Agriculture and Technology, Grant-in-Aid for Scientific Research (B), A range of techniques, including coherence scanning microscopy, three-dimensional sensing by coherence radar, and scanning white-light interferometry, have been developed for simultaneous measurement of the three-dimensional step height of discontinuous objects and tomographic imaging. These techniques, however, require mechanical scanning with a piezoelectric transducer or a precision translator. Spectral interferometry, on the other hand, potentially offers a powerful means for high-speed absolute threedimensional shape measurement of objects without moving mechanical parts. The practical applicability of such methods, however, remains limited due to the high cost of tunable lasers with sufficiently wide range (e.g., external cavity laser diodes and dye lasers) and the slow speed of data acquisition because of the large number of calculations in the Fourier transform. As an alternative interferometry-based approach, synthesis of the coherence functions has been reported to be suitable for distance measurements. This method involves pseudo-frequency comb generation by frequency modulation of a laser diode. Yet this method is not suitable for surface profilometry because the frequency-comb interval is limited to the order of megahertz. In this Letter, a novel frequency comb-based interferometry technique for profilometry and tomography is proposed. The optical frequency comb employed by this method can be adjusted simply, allowing interferometry to be performed at frequency intervals of up to gigahertz order. The method is therefore suitable for measurement of absolute distances of several micrometers to several meters without the need for mechanical movement. Step-height measurement with 9 μm accuracy was successfully performed by sweeping the comb interval frequency. Thickness measurement of a glass plate was also demonstrated. This profilometry method is expected to be useful for both surface profilometry and tomography., 16360027
2004 - 2005

New Sensing Techniques Using Spatio-temporal Dynamics of Phase Singularities in Scattered Random Optical Fields : A Basic Research
TAKEDA Mitsuo; MIYAMOTO Yoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), The purpose of this research project is to establish the basis of a new sensing technique for high-precision displacement measurement based on spatio-temporal dynamics of phase singularities in random optical fields. Because the proposed technique uses phase singularities as position markers imbedded on the surface of an object and traces the movement of the individual phase singularities, it can measure non-uniform displacement fields including rotation and scale changes, which has not been possible by conventional correlation techniques. The main achievements are summarized as in the following : 1.The generation of the pseudo-phase singularities from the complex analytic signal of a random pattern has been proposed, which enabled the use of pseudo-phase information without recourse to interferometry. 2.Displacement measurement with nanometric spatial resolution has been achieved by use of the phase singularities in the pseudo-phase distribution. 3.Measurement of large non-uniform displacements and deformations has been successfully demonstrated by use of the information about the local structure of phase singularities. 4.Phase singularities in a coherence function have been observed for the first time by experiment. Integrating all the above results, a new displacement-sensing system was developed that makes use of the phase singularities in the analytic signal of a random texture of the object and applied to the measurement of biological samples., 15360026
2003 - 2005

Optical measurement technology and application using two photon absorption (TPA) on an image sensor
KUROKAWA Takashi; TAKEDA Mitsuo; TSUDA Hiroyuki; TANAKA Yosuke
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Tokyo University Of Agriculture and Technology, Grant-in-Aid for Scientific Research (B), In normal sense, Si photodiode (Si-PD) is not sensitive to near infrared light because a band-gap of the Si crystal is generally wider than the energy of infrared light. Otherwise, in case that the Si-PD is exposed to extremely strong laser light, electric carriers are induced in proportional to the square of incident power of light according to two-photon absorption (TPA) process. By using this TPA technique, it is developed to observe an intensity correlation between two optical microwaves and between ultra-short optical pulses. The goal of this project was to progress a novel tomography with a dynamic range wider than mm to several 10mm, which is difficult to achieve with normal interferometric measurements. In 2002 fiscal year, a basic system of tomography had been investigated. As a first step, the property of the TPA process on the Si-APD (Si avalanche photodiode) was evaluated with an optical microwave by measuring an optical pass difference of two fibers in optical fiber interferometer. In order to remove noise caused by interference of carrier lights, the lights from two different optical passes, which consist of PM fibers, were combined at a right angle condition. The result proved that 1m and 2m optical pass differences were detected with 3x10^<-5> of measurement accuracy. In 2003 fiscal year, temperature dependence of output property of TPA had been studied in a viewpoint to make the measurement accuracy better. It was confirmed that the square property of the TPA process was appeared even by not only a relatively weak intensity light but also relatively strong incident light which gave intensity saturation under the condition without temperature control. Moreover, it was also confirmed to enable to measure intensity correlation without interference of carrier components independent on any polarization condition, which was obtained with beat optical microwave from two different lights at wavelength. Measurement accuracy was decided as 10^<-5>. In the other side, we also demonstrated a novel waveform measurement system of ultra-short optical pulses. Two polarization directions of divided incident lights were set at a right angle condition in order to avoid making two incident lights interfered, and was lead to an image sensor at slightly different incident angle to get auto-correlation of the pulses. In principle with this system, only one-shot gives a pulse waveform. According to a result of the experiment, 40fs waveform of ultra-short optical pulse was successfully detected., 14350032
2002 - 2003

New Principle for Optical Tomography Based on Synthesis and Control of a Three-dimensional Spatial Coherence Function : A Basic Research
TAKEDA Mitsuo; MIYAMOTO Yoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), The purpose of this research project is to establish the basis of a fundamentally new technique for synthesis and control of spatial coherence function, which enables selective creation of high coherence between a pair of desired points in three-dimensional space. Because the proposed technique uses spatial (rather than temporal) coherence function of a quasi-monochromatic light source, it opens up a new avenue to optical coherence tomography that is completely free from the dispersion problems that are unavoidable in the existing techniques of low-coherence tomography. The main achievements are summarized as in the following : 1. A theory and a methodology for designing a source distribution that produces a desired distribution of a spatial coherence function in three-dimensional space were established. In particular, a new model of fringe formation was proposed that gives a clear and intuitive picture about the relation between the source shape and the three-dimensional coherence structure. 2. A new principle for the simultaneous sensing of the object distance and the local inclination of the object surface was proposed, and the validity of the principle was verified by experiment. 3. A new scheme of phase-shift technique based on a source shape modulation by means of a spatial light modulator was proposed and verified by experiment. The proposed scheme enables phase shift completely free from a mechanically moving component, such as a piezo-electric transducer or a precision stage. Integrating all the above results, a new sensing system was developed that successfully demonstrated the shape measurement of three-dimensional structure made of a set of standard gauge blocks., 13450029
2001 - 2002

Ultra fast optical signal processing using arrayed waveguide grating
KUROKAWA Takashi; TSUDA Hiroyuki; TAKEDA Mitsuo; TANAKA Yosuke
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Tokyo University of Agriculture and Technology, Grant-in-Aid for Scientific Research (B), Ultra-short optical pulse shaping based on time-space conversion has been widely demonstrated by using free-space optics with diffraction grating pairs and lenses. We have proposed time-to-space conversion optical signal processing using an arrayed waveguide grating. The arrayed-waveguide grating system has the advantages of a long time window, and well suites to handle subpico- to several picosecond pulses. Moreover, it is compact, compatible with fiber optics, and can be integrated with functional photonic devices. We introduce several applications of this technology to terabit communication systems, such as pulse shaping, dispersion comp ensation, and optical COM encoder and decoder. Furthermore, we proposed a novel method for measuring the waveform of short optical pulses, which uses two-photon absorption process hi a silicon image sensor. We confirmed that infrared ^ht images with 1550nm wavelength were successfully, captured by the image sensor. Then we constructed a Michelson interferometer with a tilted reference mirror for measuring autocorrelation wave forms of optical pulses instantaneously without scanning mechanism., 12450027
2000 - 2001

Development of a Microscopic 3-D Shape Measuring System Using Novel Liquid-Crystal Devices
TAKEDA Mitsuo; KUROKAWA Takashi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B)., The purpose of this research project is to develop a new scheme of spectral interferometric microscopy that is free from mechanical moving components and can perform full-field 3-D shape measurement of microscopic objects with complex structures and height discontinuities exceeding the wavelength of light. The main accomplishments are summarized in the following : 1. Design and Numerical Evaluation of Liquid-Crystal Fabry-Perot Interferometers (LC-FPIs) LC-FPIs with an extended tunable range of 40nm in the near IR region (which is suitable for spectral interferometry in combination with a SLD) were designed, and their improved performances were predicted by numerical simulations. 2. Fabrication of LC-FPIs and Proposal of Their Tandem Use LC-FPIs were fabricated and their tandem use in spectral interferometry was proposed for effective improvement of the overall finesse value. 3. Design and Construction of Spectral Interferometric Microscope A spectral interferometric microscope based on the combined use of an LC-FPI and a SLD (super luminescent diode) was designed and constructed. 4. Development of Softwares for System Control and Data Acquisition Dedicated computer codes were developed for the wavelength tuning control of the LC-FPI that runs in synchronism to the fast image acquisition of the spectral interferograms. 5. Experimental Demonstration and Evaluation of the Performance of the Spectral Interference Microscope Sub-micron height resolution of the developed spectral interference microscope was demonstrated using a 3-D micro structure with 1μm and 11μm height steps fabricated on a silicon wafer., 11555012
1999 - 2000

Engineering Applications of Berry's Geometric Phase Information
TAKEDA Mitsuo; MIYAMOTO Yoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B)., The purpose of this research project is to exploit Berry's geometric phase information for engineering applications. A novel polarization interference microscope was developed that can visualize local surface inclinations of a microscopic object as a geometric phase image called a photon spin-redirection phase image. The main accomplishments are summarized in the following : 1. Experimental Detection of Photon Spin-redirection Phase Photon spin-redirection phase was detected by interferometry using circularly polarized light passing through non-planar optical paths, and its relation to the history of the beam propagation direction changes was experimentally clarified. 2. Development of Efficient Algorithm and Its Computer Code for Evaluation of Berry's Phase An efficient algorithm and computer code were developed for unified analysis and evaluation of spin-redirection and Pancharatnam phases for a beam propagating in a complex optical system. 3. Establishment of Technique for Separation of Berry Phase from Dynamical Phase A new technique of differential polarization interferometry was developed that enables selective detection of Berry phase by eliminating dynamical phase. 4. Construction and Experimental Demonstration of Berry Phase Interference Microscope An experimental system was constructed and the validity of the proposed technique was demonstrated by visualizing Berry phase introduced by local surface inclinations of 3-D micro structures on a Si wafer., 11450027
1999 - 2000

3次元微細構造の干渉計測におけるトポロジー的位相に関する研究
武田 光夫; TAVROV A. V.
日本学術振興会, 科学研究費助成事業, 電気通信大学, 特別研究員奨励費, 97F00332
1998 - 1999

Spatial Frequency Multiplex Heterodyne Technique for Absolute Measurement of Instantaneous Phase Distribution, and Its Applications
TAKEDA Mitsuo; MIYAMOTO Yoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), The purpose of this research project is to develop a new scheme of heterodyne profilometry that can perform the instantaneous measurement of the absolute phase distribution of an object with large height discontinuities and/or surface isolations. The main accomplishments are summarized in the following : 1. Invention of Spatial Frequency Multiplex and Scan Method for Absolute Phase Measurement As an alternative to the conventional temporal frequency scan method using a frequency tunable light source, a spatial frequency scan method was proposed for the absolute phase measurement. By means of spatial frequency multiplexing, the proposed technique can determine the absolute phase from a single fringe pattern, which makes possible the measurement of instantaneous phase distribution. 2. Clarification of the Relation between the Temporal and Spatial Frequency Scan Methods A unified theory was given to the basic principles of the various absolute phase measurement technique using temporal and spatial frequency scanning methods. 3. Development of New Phase Unwrapping Algorithm A new phase unwrapping algorithm that eliminates phase singular points was developed and experimentally verified. 4. Experimental Demonstration of the Instantaneous Shape Measurement of Objects in Dynamic Motion An experimental system was constructed and the validity of the proposed spatial frequency multiplex and scan method was demonstrated for objects in fast motion., 09650043
1997 - 1998

多次元波動場の位相接続技術の基礎研究
竹田 光夫
日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(C), 多次元光ヘテロダイン計測法は,干渉縞のように空間的に位相変調された「疑似周期パターン」の位相分布から測定対象の物理情報を高い分解能で抽出するための基本手段となっている.しかし,測定対象のダイナミックレンジが大きくて,位相値に換算して2πをこえると(-π,π]の主値の間に折り畳まれて位相分布に2πの不連続段差を生じる.そのため,折り畳みにより生じた不連続段差を取り除き元の位相分布を復元する位相接続法が必要とする.本研究では,干渉縞にノイズを含むスペックル干渉計測のように,従来の位相接続法が適用できない悪条件下の多次元ヘテロダイン計測により得られた位相データを接続するための新しい位相接続の基礎原理を提案し,それを現実の計測データに適用してその有効性を実験的に検証した.その具体的な内容は以下の通りである. 1.相互振幅情報を利用した位相接続法(相互振幅最大木法)の提案 大きなノイズの存在する場合,従来法では(-π,π]に折り畳まれた位相分布をどの画素から順に位相接続していくかの接続経路の選択により全く異なる位相分布が得られてしまう.そこで,本研究では,正しい位相分布にできるだけ近い結果を与える位相接続経路の選択するための新戦略として,これまで捨てられていた振幅情報を用いることにした.まず,疑似周期パターンの振幅の大きなところは干渉縞でいうと縞のコントラストが高く位相の計測値の信頼性が高いということに着目し,隣接する画素間の位相計測値の相互信頼度の測度として「相互振幅」という新しい概念を導入した.そして,「相互振幅」の大小により画素間の位相計測値の相互信頼度の優劣のランクづけをして信頼度の高い画素間を優先的に接続するように位相接続経路を選択する新しい位相接続法を提案した.また,それを実現するための具体的なアルゴリズムが画素を節とし「相互振幅」を枝の重みとする平面グラフの最大木探索問題となることを示した. 2.位相情報を利用した既存の方法との比較による優位性の実証 相互振幅情報を利用した我々の方法と比較すべき既存の方法として,計算効率と位相接続能力がともに優れているとして国際的に知られている「位相差最小木法」を選んだ.これは,隣接する画素間の「位相差」を画素間の位相計測値の相互信頼度の測度とするもので,画素を節とし「位相差」枝の重みとするグラフの最小木を構成しそれを位相接続経路とする方法である.物体自身に不連続位相を持つ3次元立体計測の実験とスペックルノイズの干渉計測の計算機シミュレーションの両方により悪条件下の位相接続能力を比較した.その結果,われわれの提案した方法の優位性が検証された., 07650048
1995 - 1995

フーリェ縞解析法による結晶の原子配列歪のサブ・オングストローム計測
武田 光夫
日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(B), 最近,透過電子顕微鏡(TEM)や走査トンネル顕微鏡(STM)の技術進歩はめざましく,これらの高分解能顕微鏡により結晶の原子配列を直接観測することができるようになり,転位や格子間隔の拡縮や超格子歪みなどの結晶中の空間配列の乱れの分布の精密測定への期待が高まってきている.このような背景のもとで,本研究は,我々がこれまで光応用計測の分野において開発してきた画像処理技術を原子スケールの顕微鏡像の解析に応用したものであり,その具体的な内容は以下の通りである. 1.結晶格子歪みの空間周波数ヘテロダイン検出法の考案 原子配列に乱れのある結晶の疑似周期的な格子像の歪の形状と,波面に乱れを持つ光波にティルトを与えて干渉させた時に生じる位相変調された空間キャリア干渉縞の歪の形状との間の類似性に着目し,TEMやSTMにより得られる原子配列像を空間キャリア周波数をもつ干渉縞とみなして空間周波数ヘテロダイン検出することにより,非常に高い分解能で精密計測する方法の基本原理を考案した. 2.フーリェ変換縞解析法による格子歪分布計測の原理の有効性の検証 我々が光波の干渉縞解析のために開発したフーリェ変換縞解析法が結晶格子歪の空間周波数ヘテロダイン検出のための具体的手段として有効であることをシミュレーションと実験により検証した. 1.1 計算機シミュレーションにより作成した既知の結晶格子像を用いた精度の確認 計算機内部で既知の格子歪分布値をもつ種々の結晶格子像を数値的に作成し,それらを空間キャリア干渉縞と見なしてフーリェ変換法により原子の基準位置からの変位分布を求め,数値的に与えた既知の変位分布と比較することにより格子間隔の1/30以下の格子歪の検出の可能性を確認した. 1.2 実際の結晶を対象とした転位や格子間隔の拡縮などの計測実験 シリコン(Si)や金(Au)の結晶の刃状転位のように格子の歪分布がの概形が知られている試料のTEM像を対象に実験をおこない格子の微小変位分布の検出することにより原理の有効性を実証した., 06452129
1994 - 1994

多次元情報画像処理
大塚 喜弘; 伊東 一良; 藤原 裕文; 武田 光夫; 小川 英光; 稲場 文男; 辻内 順平
日本学術振興会, 科学研究費助成事業, 北海道大学, 重点領域研究, 直交2周波局部発振光を有する時空間広帯域光ヘテロダイン偏光計を試作し、動的複屈折分布応答の時空間分布を画像表示するとともに、当該偏光計の有用性を実証した。 生体からの超微弱発光現象としてのバイオフォトンの2次元発光パターン情報の高感度計測・処理法の研究開発を行い、新しい画像を得るとともに、新知見を得ることに成功した。また、この現象の量子光学的特性の解明を試み、検討を行った。 瞬時の分光画像計測を目的とする並列多重フーリエ分光映像法を開発し、その有用性を確認した。本法では、レンズアレイを用いて物体の多重像を作り、それぞれの像に異なる光路差を与えるものであり、高速回転物体の瞬時の分光画像計測に成功した。 セルオートマトン、多変量のファジー論理回路、乗算のようなディジタル数値演算を光デバイスによって実現する方法を開発するとともに、画像処理をカスケート接続された光デバイスによって実現する方法を開発した。 干渉計の縞画像走査における時空間縞縮退現象を利用することにより、物理的に実在しない波動場でありながら、あたかも実在する波動によって生ずる干渉縞のごとき「仮想波面」を発生する原理を提案し、その実証実験により有用性を示した。 時定数の異なる2種類の有機色素を高分子に分散させた膜を作成し、互いに直交偏光状態にある位相共役波の発生に成功した。これを用いて、入力画像の中から動画像のみを抽出することを可能とした。 BSO結晶を用いた結合フーリエ変換相関器を開発し、高速画像相関演算を行った。結晶内の光強度不均一性を改善することにより、正しい相関関数の得られることを示した。, 04228101
1993 - 1993

Mamalian-like neural networks for dynamic information processing and its learning algorithm
TAKAHASHI Haruhisa; TAKEDA Mitsuo; TOMITA Etsuji
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for General Scientific Research (C), (1)It is mathematically investigated as to what kind of internal representations are separable by a single output unit of a three layr feednext neural network. A topologically described necessary and sufficient condition is shown for partitions of input spaces to be classified by the output unit. Then an efficient algorithm is proposed for checking if a given partition of the input space is resulted in linear separation at the output unit. (2)(3)These papers improves the sample complexity needed for reliable generalization in the PAC learnability in machine learning. By introducing an ill-posed learning algorithm which gives error worse over the candidates of network realizarions that are attained by minimizing empirical error, we can refine the order of the sample complexity, whereas the previous methods seek the uniform error over the whole configuration space. Essential VC dimension of concept classes, which is smaller than or equal to the number of modifiable system parameters, is introduced for calculating the generalization error instead of the traditional VC dimension analysis. Noisy learning is also treated. (4)In this paper we propose a very simple recurrent neural network(VSRN)architecture which is a three-layr network and contains only self-loop recurrent connections in the hidden layr. The role of the recurrent connection is explained by the network dynamic and its function will be acquired by learning from finite examples like a mamalian action. Through the learning process some characteristic functions observed in the mamalian auditory systems are found automatically acquired by the network. These contain on-neuron, off-neuron and on-off-neuron. This architecture can perform phoneme spotting in real time by utilizing these characteristic functions. Some simulation experiments are done to investigate the recognition performance., 04805032
1992 - 1993

高密度に集績化された光論理デバイス用アレー・イルミネータの研究
久保田 敏弘; 武田 光夫
日本学術振興会, 科学研究費助成事業, 京都工芸繊維大学, 一般研究(C), 我々はグレイティングカプラを使った光導波路型のコンパクトなアレー・イルミネータを提案し、その原理の確認と光の利用効率について解析を行なってきた。本研究はその基礎の上にたって、光導波路型の特長に自由空間の伝播を利用する特長を併せもった、高密度に集積化された高効率のイルミネータを設計・作製することを目的としている。これを達成するために、以下の研究を行なった。 (1)グレイティングカプラの理論解析 グレイティングの形状の回折効率依存性を理論的に求めた。溝の形状が正弦状であるとした場合、溝の深さが小さい範囲では2次関数的に変化する。-1次項(空気側)の回折効率の最大値は、溝の深さ0.38μmで0.315である。また-2次項(戻り光)は溝の深さ0.85μm付近で0.98程度まで達することがわかった。 (2)グレイティングカプラの作製と性能評価 2光束干渉法によりフォトレジストに干渉縞を記録し、グレイティングカプラを作製した。回折効率を測定し、同時にその断面の電子顕微鏡観察を行なって溝の深さを読み取り、理論解析の結果を確かめた。全次数の回折効率の和を求めた結果は0.85程度であり、散乱および吸収は数%と低いことがわかった。 (3)アレー・イルミネータの作製 これらの結果に基づいて、均一のビームの得られるアレー・イルミネータを設計した。ビームの数は10本と20本である。実験によって露光量と回折効率の関係を求め、ビームの出射位置によって露光量を変えることにより回折効率を制御し、10×20本のほぼ均一なビームの得られるアレー・イルミネータを作製することができた。これらの成果を応用物理学会などに発表した。, 04650040
1992 - 1992

時空間スペックルグラムの周波数解析による立体計測法の研究
武田 光夫
日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(C), 従来の代表的な非接触立体計測法であるモアレ法は,連続で滑らかな形状の物体に対しては有効であるが,モアレ縞の縞次数に飛びが生じるような強い段差や不連続性をもつ物体は測定できない.また,ステレオ視差法は,ステレオ画像の対応点決定の計算量が多いという問題に加えて,反射率が一様な表面を持つ物体の場合には照合する特徴点が得られないという問題がある.本研究では,従来の立体計測法が対応できないこれらの物体の形状を非接触で自動計測することを目的として以下のように新しい立体計測法の原理を考案し実験によりその有効性を実証した. (1)従来のモアレ法やステレオ視差法のような基線を媒介とした3角測量法的な原理に代わるものとして,光波干渉を利用した直接的な2点間測距の原理を採用し,それを被測定物体上の全点に対して多点同時並列的に実現するような新しい方法の原理を考案した.粗面物体を測定できるようにスペックル干渉計と類似な光学系を用いたが,スペックル干渉計測法は物体の元の位置・形状からの相対的な変位・変形を測る,いわば差分量△hの計測技術であったのに対して,本研究の方法は,位置・形状そのもの,すなわちh自身の計測技術である点にその特長と新規性がある. (2)光源に波長走査可能な半導体レーザを用い,干渉計のなかにテレセントリック結像系を導入し,物体をイメージセンサ上に共役結像することにより,粗面物体上の各点からの散乱光を再統合して各点が互いに独立な干渉光路をもつ(画素と同数の)超多チャンネル測距干渉計が実現できることを見いだし,上述の原理に基づく立体計測システムを構築した. (3)段差のある針状物体や深穴の形状を非接触自動測定することにより原利の有効性を実験的に確認した., 04650035
1992 - 1992

多次元情報画像処理
大塚 喜弘; 藤原 裕文; 辻内 順平; 武田 光夫; 小川 英光; 稲場 文男
日本学術振興会, 科学研究費助成事業, 北海道大学, 重点領域研究, 直交2成分を有する参照光を干渉計に導入し、新しい偏光干渉計を試作した。これにより、光波の偏光状態の時空間分布のマッピングが可能なことを示すとともに、光弾性材料の新しい研究方法を提示した。 液晶偏光干渉計を開発し、分光映像装置の入射光量を格段に増加することができた。これにより、デ-タ圧縮された分光画像の高速空間領域分割の有用性が確認された。 コヒ-レント光検出・画像計測法を開発し、ガン組織などの生体試料の断層画像に関する基礎研究を行なうとともに、被測定生体対象の位相情報検出のための光へテロダイン計測システムの構成と基礎実験を行った。 ニュ-ラルネット学習において、過学習の生ずる条件と過学習を防止する方法を明らかにした。また、バックプロパゲ-ションの汎化能力を解明し、作用素論的枠組から最適汎化ニュ-ラルネットの理論を構築した。 時空間融合の位相情報の多重化と実現方法を提案し、予備実験によりその有効性を確認した。さらに、位相共役増幅機講により生成される光波の時空間特性とニュ-ラルネットの類似性を見出した。 BSO結晶を用いてJoint Transform Correlationの手法により、光学的連想メモリ-の実験を行った。書き込みをアルゴンレ-ザ-で、読み出しをHeーNeレ-ザ-で行って、結晶の特性との関連を調ベた。 キサンテン系やアゾ系の有機色素膜を用いて、2次元画像の実時間演算を行う際に問題となる位相共役波発生効率、ホログラフィ成分の時間変動、自己回折効率、並びに、複屈折差などに関する基礎デ-タを得た。, 03244101
1991 - 1991

Development and Evaluations of Efficient Algorithms for Finding a Maximum Clique Based upon Nueral Networks
TOMITA Etsuji; YOKOMORI Takashi; TAKEDA Mitsuo; TAKAHASHI Haruhisa
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The Univesity of Electro-Communications, Grant-in-Aid for General Scientific Research (C), 1. Given a graph of n nodes, we have devised an 0(n^3)-time algorithm NMCLIQ for finding a near-maximum clique. We have confirmed in experiments for several graphs with up to 400 nodes that the orders of maximal c)iques found by NMCLIQ are almost more than 85% of the maximum orders. 2. We have developed an 0(n^3)-time algorithm RACLIQUE for finding a near-maximum clique in a given graph of n nodes. While the algorithm is based upon the notion of Boltzmann machines, it employs no simulated annealing and hence is simple to control its execution. We have confirmed in experiments for several random and nonrandom graphs with up to 400 nodes that almost optimum solutions can be found very efficiently. In addition, further improvements and variations are considered and verified to be very useful. 3. We have devised two non-searching algorithms for the n-queen problem which are based upon the former resuit for finding a near-maximum clique. We have confirmed in experiments for up to 50, 000 queens that they are extremly efficient., 02650261
1990 - 1991

Development and Applications of Learning Algorithms for Neural Networks
TAKAHASHI Haruhisa; TAKEDA Mitsuo; TOMITA Etsuji
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Elector-Communications, Grant-in-Aid for General Scientific Research (C), (1)It is mathematically investigated as to what kind of internal representations are separable. by a single output unit of a three layer feed next neural network. A topologically described necessary and sufficient condition is shown for partitions of input spaces to be classified by the output unit. Then an efficient algorithm is proposed for checking if a given partition of the input space is resulted in linear separation at the output unit. (2)We propose in this paper a new recurrent propagation learning algorithm. A biologically plausible neurodynamics is derived from which a quick algorithm to compute fixed points is obtained applying an approximation of stochastic process. The sensitivity of the networks is also obtained and from that a new recurrent propagation teaming algorithm is proposed. Our algorithm can run 10 times more quick over the previous ones. Furthermore, some unstable problems in recurrent propagation are overcome. Some simulation results are given to compare the recurrent propagations with Backpropagation and Mean Field Networks. (3)Associative memory is realized by the, recurrent propagation Teaming rule as equilibrium states ; of the network. Since the number of hidden units can be increased unrestrictedly, the information capacity can be sufficiently large. This is the main advantage of the proposed network compared with previous ones that have no hidden units. Some printer fonts are used for patterns to be memorized in our experiments. The data show that the more the number of hidden units, the more the rate of memorization and correct association. (4)A new teaming network is proposed in this chapter. Although the Backpropagation Teaming method has been succeeded in many applications, some difficulties exists, such as the local minimal problem, too long Teaming Teaming times, and capability of approximation to continuous mappings. We combine the competitive learning and supervised teaming methods in order to approximate continuous mappings. Some simulation results show that the proposed teaming algorithm works extremely more quick than the Back Propagation method and has reliable convergence property., 02650235
1990 - 1991

Digital Optical Processing System Using Holograms
OHZU Hitoshi; MURAOKA Youichi; TAKEDA Mitsuo
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, WASEDA University, Grant-in-Aid for General Scientific Research (B), A digital optical processing system using holograms is studied. Optical digital circuits consist of holographic logic operations are investigated and demonstrated. Devices for practical use are proposed and the experimental results are shown. Holographic logic operations have parallelism, however, can perform only one kind of operations. Since different kinds of logic operations are required in order to construct digital circuits, local variable logic operations, which can perform different operations at different positions, are proposed. The local variable logic operations are combined in order to construct holographic logic modules. Optical digital circuits are constructed by interconnecting the modules regularly. High diffraction efficiency holograms are important, since the power consumption of the optical computing systems depends on the efficiency. In this study, ROACHs are introduced, which have high diffraction efficiency and have high accuracy of amplitude and phase distribution. The diffraction efficiency of 10% is achieved by use of the holograms. The ROACH has two layers for amplitude modulation and phase modulation, each layer for each modulation. In this study, compensation in the amplitude modulation layer is found to be required, since the amplitude modulation occurs in the phase modulation layer. High speed spatial light modulators are also important in order to construct the digital optical computers. In this study, optical bistable devices, which have high speed nonlinear effects, are employed as the spatial light modulators. Researches of two dimensional characteristic of the optical bistable devices have not been performed. The MTF of the devices are measured, and resolution of 80 lines/mm is obtained at the contrast of 50%. It means that one device consists of array of 13mum X 13mum nonlinear elements. The switching power of each element is 0.8mW and the switching time is 80mus., 02455025
1990 - 1991

非線形光波増幅機構を用いた複素ニュ-ロン場の生成に関する基礎研究
武田 光夫
日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(B), 本研究では波動場によって形成される「複素ニュ-ロン場」という新しい概念を提案し,そのダイナミックスの基本的な性質を明らかにした.その具体的な成果は以下の通りである. <1.光波動場の物理現象とニュ-ラルネットの対応関係の明確化>___ー 振幅と位相の情報を持つ複素波動場をニュ-ロンの複素状態変数に対応させると,1点から発した光波が他の1点に到達する間にうける振幅の減衰と位相変化を複素シナプシス結合荷重に対応させることができることを示した.また,光波伝播の相反性により複素光波動場の形成する複素ニュ-ロン場の複素シナプシス荷重は一般に対称性を持つことを明らかにした. <2.複素ニュ-ロン場のエネルギ-関数の発見とその存在条件の提示>___ー 複素シナプシス結合荷重が対称性を持つ場合とエルミ-ト対称性を持つ複素ニュ-ロン場に対しては,従来の実数ニュ-ラルネットと類似のホップフィ-ルド・エネルギ-関数が存在することを見いだした.また,それらのエネルギ-関数を持つ複素ニュ-ロン場を複素光波動場で実現するには位相共役波発生機構の存在が不可欠な条件であることを明らかにした. <3.実験によるモデルの妥当性の検討>___ー 複素ニュ-ロン場の生成システムとして縮退4波混合による位相共役波発生の際の光増幅機能と球面鏡を組み合わせた光フィ-ドバック系を提案し,その複素波動場の振舞いを計算機シミュレ-ションによる実験で調べ,提案したエネルギ-関数が確かに時間とともに単調減少し,波動場が最終的に光共振器の固有モ-ドの1つに収斂して行くことを確認した.実際のレ-ザ-のポンプ光からエネルギ-供給を受けたBaTiO_3結晶の持つ非線形光波増幅機能による実験は現在進行中であり,我々の予見したエネルギ-関数の振舞いをまだ直接確認するには至っていないが,近くその性質を明らかにできるものと期待している., 02452085
1990 - 1990

Basic Research on Three-Dimensional Free-Space Optical Interconnects Using Holographic Optical Elements
TAKEDA Mitsuo; KUBOTA Toshihiro
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, UNIVERSITY OF ELECTRO-COMMUNICATIONS, Grant-in-Aid for General Scientific Research (B), The research was carried out with the aim of developing a novel holographic element for three-dimensional free-space optical interconnects, and the following results have been obtained: 1. Proposal of the basic principle of an array illuminator We have proposed a new scheme for implementing array illuminators. which are used to distribute optical power to an array of optical logic gates or bistable devices that require optical power supplies. The scheme is based on integrated optics, and has the advantage that the system becomes compact and that alignment problems can be greatly alleviated. 2. Design for an array illuminator using a grating coupler, and establishment of a theory to predict the performance of the illuminator We have proposed a design principle for an array illuminator using a grating coupler. We have shown that it is possible to design an array illuminator that generate uniform beams with 100% power efficiency. We have also shown that the product of the number of beams and the beam compression ratio becomes a constant, which sets the fundamental limitation of the scheme proposed. 3. Fabrication of array illuminators and experimental demonstrations of the validity of the principfe We first fabricated one-dimensional array illuminators based on the proposed principle. Then, we made a two-dimensional array illuminator by combining the two one-dimensional array illuminators. By introducing a laser beam into the array illuminator, we have experimentally demonstrated that a two-dimensional array beams can be obtained., 63460065
1988 - 1989

光強度輸送方程式に基づく位相センシングの研究
武田 光夫
日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(C), 干渉計測の手段を用いることができない状態下で強度情報だけから光波の位相を求める問題は位相回復問題と呼ばれ, 光学のみならずX線や電子線のような低コヒーレンス波動場の計測の基礎となる非常に重要な問題である. 位相回復問題に対する従来の研究は, 強度の非負性を拘束条件とした反復法または複素平面場上の解析接続などの数学的手法に基づくものが主流であるが, ノイズの影響を受けやすいことや解の一意性が保証されない点が実用化の障害になっていて, 多くはコンピュータシミュレーションによる原理の確認に留まっていた. そこで, 本研究では, 光強度だけでなく光強度の空間的微係数をあわせて計測することにより, 簡単な計算で解を一意に決定することができる実用性のある手法を開発し, その有効性を実験により確認した. その具体的な内容は以下の通りである. 1.波動方程式から出発して, 光強度と位相との関係を直接表現するような形式の光強度輸送方程式を導き, 境界条件として強度とその空間的微係数を与えることにより位相を一意に求めることができる新しい測定原理を提案し, その計算のためのアルゴリズムを明らかにした. 2.2次元光強度分布とその空間的微係数を測定するために, 軽量CCDカメラを精密微動装置上に搭載し前後に微小移動させてフレームメモリに光強度分布を蓄えるシステムを試作し, 空間的にインコヒーレントな純単色光源で照明された位相物体の位相を計測する実験を行い有効性を実証した. 従来の方法は光強度のみから位相を決定しようとしたのに対し, 本方法はさらに光強度の空間的微係数をあわせて測定し, より多くの情報を利用してその分だけ数学的計算と原理の簡単化をはかろうとする点を特色とする. 本研究の成果は, コヒーレンスの高い光源が得にくい電子線やX線の分野の位相計測への応用が期待できる., 62550026
1987 - 1987

Homomorphic Filtering の光計測への応用
武田 光夫
日本学術振興会, 科学研究費助成事業, 電気通信大学, 一般研究(C), 58550028
1983 - 1983

透過波面計測装置及び透過波面計測方法
Patent right, 小野 明, 武田 光夫, 大谷 幸利, 谷田貝 豊彦, 特願2014-169226, Date applied: 22 Aug. 2014, 国立大学法人宇都宮大学, 特開2016-045070, Date announced: 04 Apr. 2016,

撮像装置および画像処理方法
Patent right, 長井 健太郎, 武田 光夫, 特願2011-248717, Date applied: 14 Nov. 2011, キヤノン株式会社, 特開2013-102951, Date announced: 30 May 2013, 特許第5868132号, Date issued: 15 Jan. 2016,

透過波面計測装置及び透過波面計測方法
Patent right, 喜入 朋宏, 武田 光夫, 谷田貝 豊彦, 小野 明, 特願2013-174970, Date applied: 26 Aug. 2013, 国立大学法人宇都宮大学, 特開2015-042967, Date announced: 05 Mar. 2015,

撮像装置および画像処理方法
Patent right, 長井 健太郎, 武田 光夫, 特願2011-248717, Date applied: 14 Nov. 2011, キヤノン株式会社, 国立大学法人電気通信大学, 特開2013-102951, Date announced: 30 May 2013,

空間モード同期レーザ
Patent right, 黒川 隆志, 武田 光夫, 特願2012-011416, Date applied: 23 Jan. 2012, 国立大学法人東京農工大学, 国立大学法人電気通信大学, 特開2012-080134, Date announced: 19 Apr. 2012,

位相特異点検出方法、及び、位相特異点検出装置、並びに、プログラム
Patent right, 武田 光夫, ワン ウェイ, 横関 友亮, 石島 玲華, 特願2006-117103, Date applied: 20 Apr. 2006, 国立大学法人電気通信大学, 特開2007-292468, Date announced: 08 Nov. 2007, 特許第4820998号, Date issued: 16 Sep. 2011,

光波干渉測定装置
Patent right, 葛▼ 宗濤, 武田 光夫, 特願2007-030777, Date applied: 09 Feb. 2007, 富士フイルム株式会社, 国立大学法人電気通信大学, 特開2008-196901, Date announced: 28 Aug. 2008, 特許第4810693号, Date issued: 02 Sep. 2011,

三次元形状測定装置
Patent right, ミハル パヴロフスキー, 武田 光夫, 木村 高啓, 特願2007-292911, Date applied: 12 Nov. 2007, アンリツ株式会社, 国立大学法人電気通信大学, 特開2009-121828, Date announced: 04 Jun. 2009, 特許第4756024号, Date issued: 03 Jun. 2011,

生成装置および方法、測定装置および方法、並びにプログラム
Patent right, 段 志輝, 武田 光夫, 特願2005-094689, Date applied: 29 Mar. 2005, 国立大学法人電気通信大学, 特開2006-275740, Date announced: 12 Oct. 2006, 特許第4701388号, Date issued: 18 Mar. 2011,

測定装置および方法、並びにプログラム
Patent right, 段 志輝, 武田 光夫, 特願2005-094688, Date applied: 29 Mar. 2005, 国立大学法人電気通信大学, 特開2006-275739, Date announced: 12 Oct. 2006, 特許第4701387号, Date issued: 18 Mar. 2011,

微小変位計測法及び装置
Patent right, 武田 光夫, 王 ▲うぇい▼, 石井 信生, 宮本 洋子, 特願2006-512596, Date applied: 22 Apr. 2005, 国立大学法人電気通信大学, 特許第4644819号, Date issued: 17 Dec. 2010,

三次元形状計測装置
Patent right, 武田 光夫, ミハル, エマニュエル, パヴロフスキー, 坂野 洋平, 特願2006-549056, Date applied: 22 Dec. 2005, 国立大学法人電気通信大学, 特許第4411441号, Date issued: 27 Nov. 2009,

変位検出方法、及び、変位検出装置、変位検出プログラム、並びに、位相特異点マッチング処理方法、位相特異点マッチング処理プログラム
Patent right, 武田 光夫, ワン ウェイ, 横関 友亮, 石島 玲華, チャオ ユー, 特願2007-556824, Date applied: 24 Jan. 2007, 国立大学法人電気通信大学, 特許第4385139号, Date issued: 09 Oct. 2009,

三次元形状測定装置
Patent right, ミハル パヴロフスキー, 武田 光夫, 木村 高啓, 特願2007-292911, Date applied: 12 Nov. 2007, アンリツ株式会社, 国立大学法人 電気通信大学, 特開2009-121828, Date announced: 04 Jun. 2009,

三次元形状測定装置
Patent right, 松岡 利幸, 辻村 映治, 菅井 雅也, 武田 光夫, ミハル, パヴロフスキー, 特願2006-006729, Date applied: 13 Jan. 2006, アンリツ株式会社, 国立大学法人 電気通信大学, 特開2007-187585, Date announced: 26 Jul. 2007, 特許第4218809号, Date issued: 21 Nov. 2008,

光波干渉測定装置
Patent right, 葛▼ 宗濤, 武田 光夫, 特願2007-030777, Date applied: 09 Feb. 2007, フジノン株式会社, 国立大学法人 電気通信大学, 特開2008-196901, Date announced: 28 Aug. 2008,

空間モード同期レーザ
Patent right, 黒川 隆志, 武田 光夫, 特願2006-303422, Date applied: 08 Nov. 2006, 国立大学法人東京農工大学, 国立大学法人 電気通信大学, 特開2008-124087, Date announced: 29 May 2008,

位相特異点検出方法、及び、位相特異点検出装置、並びに、プログラム
Patent right, 武田 光夫, ワン ウェイ, 横関 友亮, 石島 玲華, 特願2006-117103, Date applied: 20 Apr. 2006, 国立大学法人 電気通信大学, 特開2007-292468, Date announced: 08 Nov. 2007,

変位検出方法、及び、変位検出装置、変位検出プログラム、並びに、特徴点マッチング処理方法、特徴点マッチングプログラム
Patent right, 武田 光夫, ワン ウェイ, 横関 友亮, 石島 玲華, チャオ ユー, JP2007051095, Date applied: 24 Jan. 2007, 国立大学法人 電気通信大学, WO2007-088759, Date announced: 09 Aug. 2007,

三次元形状測定装置
Patent right, 松岡 利幸, 辻村 映治, 菅井 雅也, 武田 光夫, ミハル, パヴロフスキー, 特願2006-006729, Date applied: 13 Jan. 2006, アンリツ株式会社, 国立大学法人 電気通信大学, 特開2007-187585, Date announced: 26 Jul. 2007,

測定装置および方法、並びにプログラム
Patent right, 段 志輝, 武田 光夫, 特願2005-094688, Date applied: 29 Mar. 2005, 国立大学法人 電気通信大学, 特開2006-275739, Date announced: 12 Oct. 2006,

生成装置および方法、測定装置および方法、並びにプログラム
Patent right, 段 志輝, 武田 光夫, 特願2005-094689, Date applied: 29 Mar. 2005, 国立大学法人 電気通信大学, 特開2006-275740, Date announced: 12 Oct. 2006,

カメラ付き携帯型電話機
Patent right, 黒川 隆志, 阿部 晋一, 武田 光夫, 特願2005-035175, Date applied: 10 Feb. 2005, 株式会社ヒューマンテクノロジーズ, 特開2006-222810, Date announced: 24 Aug. 2006,

三次元形状計測装置
Patent right, 武田 光夫, ミハル, エマニュエル, パヴロフスキー, 坂野 洋平, JP2005023586, Date applied: 22 Dec. 2005, 国立大学法人 電気通信大学, WO2006-068217, Date announced: 29 Jun. 2006,

微小変位計測法及び装置
Patent right, 武田 光夫, 王 ▲うぇい▼, 石井 信生, 宮本 洋子, JP2005007683, Date applied: 22 Apr. 2005, 国立大学法人 電気通信大学, WO2005-103610, Date announced: 03 Nov. 2005,

光接続集積回路
Patent right, 武田 光夫, 林 厳雄, 小柳 光正, 特願平4-343785, Date applied: 24 Dec. 1992, 林 厳雄, 特開平6-045584, Date announced: 18 Feb. 1994, 特許第3629713号, Date issued: 24 Dec. 2004,

非接触形状測定方法
Patent right, 武田 光夫, 青木 隆浩, 特願平11-200481, Date applied: 14 Jul. 1999, 株式会社オプトン, 特開2001-027517, Date announced: 30 Jan. 2001, 特許第3595736号, Date issued: 10 Sep. 2004,

3次元形状測定方法
Patent right, 武田 光夫, 與語 照明, 田中 秀行, 顧 若偉, 特願2001-122723, Date applied: 20 Apr. 2001, 與語 照明, 特開2002-318109, Date announced: 31 Oct. 2002, 特許第3519698号, Date issued: 06 Feb. 2004,

3次元形状測定方法
Patent right, 武田 光夫, 木下 雅也, 顧 全, 高井 英明, 高橋 洋祐, 特願平9-050566, Date applied: 05 Mar. 1997, 株式会社オプトン, 特開平10-246612, Date announced: 14 Sep. 1998, 特許第3388684号, Date issued: 17 Jan. 2003,

3次元形状測定方法
Patent right, 武田 光夫, 與語 照明, 田中 秀行, 顧 若偉, 特願2001-122723, Date applied: 20 Apr. 2001, 與語 照明, 特開2002-318109, Date announced: 31 Oct. 2002,

光導波路の製造方法
Patent right, 中村 徹, 田上 知紀, 加藤 猛, 武田 光夫, 特願平5-330503, Date applied: 27 Dec. 1993, 株式会社日立製作所, 特開平7-191224, Date announced: 28 Jul. 1995, 特許第3345143号, Date issued: 30 Aug. 2002,

非接触形状測定方法
Patent right, 武田 光夫, 青木 隆浩, 特願平11-200481, Date applied: 14 Jul. 1999, 株式会社オプトン, 特開2001-027517, Date announced: 30 Jan. 2001,

3次元形状測定方法
Patent right, 武田 光夫, 木下 雅也, 顧 全, 高井 英明, 高橋 洋祐, 特願平9-050566, Date applied: 05 Mar. 1997, 株式会社オプトン, 特開平10-246612, Date announced: 14 Sep. 1998,

高集積光導波路
Patent right, 中村 徹, 田上 知紀, 加藤 猛, 武田 光夫, 特願平5-330503, Date applied: 27 Dec. 1993, 株式会社日立製作所, 特開平7-191224, Date announced: 28 Jul. 1995,

光接続集積回路
Patent right, 武田 光夫, 林 巌雄, 小柳 光正, 特願平4-343785, Date applied: 24 Dec. 1992, 財団法人光産業技術振興協会, 特開平6-045584, Date announced: 18 Feb. 1994,