Misc - NOMURA Takanori

Multiwavelengths holgoraphic image fusion using 2D discrete wavelet transform

Proc. Soc. Photo-Opt. Instrum. Eng.   6016   2005

An input phase mask desinged for optical space bandwidth

Optics in Information Systems (SPIE Int. Technical Group Newsletter)   16, 2, 5   2005

Multiwavelengths holgoraphic image fusion using 2D discrete wavelet transform

Proc. Soc. Photo-Opt. Instrum. Eng.   6016   2005

Hybrid optical encryption of a three-dimensional object

Optics in Information Systems (SPIE Int. Technical Group Newsletter)   16, 1, 5   2005

An input phase mask desinged for optical space bandwidth

Optics in Information Systems (SPIE Int. Technical Group Newsletter)   16, 2, 5   2005

Quasi one-shot phase-shifting digital holography

Takanori Nomura, Shinji Murata, Eiji Nitanai, Takuhisa Numata

Proceedings of SPIE - The International Society for Optical Engineering   6016   2005

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The quasi one-shot phase-shifting digital holography using phase difference of orthogonal polarizations is proposed. The use of orthogonal polarizations can make it possible to record two phase-shifted holograms simultaneously. By combining the holograms with distributions of a reference wave and an object wave, the complex field of the wavefront of a 3D object can be obtained. As two phase-shifted holograms can be obtained simultaneously in the proposed method, even a moving object can be recorded.

DOI

Optical encryption based on the input phase mask designed for the space bandwidth of the optical system

Takanori Nomura, Bahram Javidi

Proceedings of SPIE - The International Society for Optical Engineering   5908   1 - 8   2005

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To improve the image quality of the decrypted image through the double-random phase-encoding optical encryption, the design method of the input phase mask is proposed. The input phase mask is iteratively designed so that the extent of the Fourier spectrum of the product of an input image and the input phase mask matches to the space bandwidth of the optical system. By using the designed input phase mask, we show that the bit-error rate is improved. We also discuss the number of the phase levels of the designed input phase mask.

DOI

Hybrid optical encryption of a 3-D object using a digital holographic technique

T Nomura, K Uota, Y Morimoto

OPTICAL ENGINEERING ( SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS )  43 ( 10 ) 2228 - 2232   2004.10

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An encryption method of a 3-D object based on the phase modulation of an object wave is proposed. The phase of the object wave is modulated by a virtual optical random phase mask using a digital holographic technique. The keys of an encryption step are both a phase distribution and a position of the virtual optical phase mask. If either of them is not correct, we cannot decrypt the 3-D object. Owing to a characteristic of a hologram, we can see some parallax of a reconstructed 3-D object. Experimental results are presented to confirm the proposed method. (C) 2004 Society of Photo-Optical Instrumentation Engineers.

DOI

ディジタルホログラフィー技術を用いた3次元物体の光暗号化記録

野村 孝徳

光技術コンタクト ( 日本オプトメカトロニクス協会 )  42, No. 6 pp. 292-298 ( 6 ) 292 - 298   2004

Out-of-plane Displacement Measurement Using Phase-shifting Digital Holography

TAKAHASHI Isao, MORIMOTO Yoshiharu, NOMURA Takanori, YONEYAMA Satoru, FUJIGAKI Motoharu

日本機械学会関東支部総会講演会講演論文集 ( The Japan Society of Mechanical Engineers )  2003 ( 9 ) 175 - 176   2003.03

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The out-of-plane displacement of a cantilever is measured by phase-shifting digital holography. Fourier transform phase-shifting method is used for phase analysis. The 36 holograms with phase-shift are recorded by a CCD. The complex amplitude of the CCD plane is obtained using the Fourier transform phase-shifting method. The complex amplitude of reconstructed plane is obtained from the complex amplitude of the CCD plane using Fresnel diffraction algorithm. A difference of the phase distribution of before and after deformation, i.e. out-of-plane displacement is calculated. The smooth phase difference is obtained by the Fourier transform phase-shifting method.

フーリエ変換位相シフト法とエイリアシングを用いた同時4ビームモアレ干渉縞解析

山本 裕子, 森本 吉春, 野村 孝徳

日本実験力学会講演論文集 ( 日本実験力学会 )  ( 3 ) 79 - 84   2003

位相シフトデジタルホログラフィを用いた段差のある物体の変位計測

高橋 功, 森本 吉春, 野村 孝徳

日本実験力学会講演論文集 ( 日本実験力学会 )  ( 3 ) 89 - 91   2003

レーザ干渉法を用いた計測におけるノウハウ (合同ワークショップ2003「実験力学における計測・データ処理の問題点・ノウハウ・工夫」)

森本 吉春, 野村 孝徳, 藤垣 元治

日本実験力学会講演論文集 ( 日本実験力学会 )  ( 3 ) 1 - 7   2003

Secure optical data storage with random phase key codes by use of a configuration of a joint transform correlator

NOMURA T, MIKAN S, MORIMOTO Y, JAVIDI B

Applied Optics   42 ( 8 ) 1508 - 1514   2003

DOI

Secure optical data storage with random phase key codes by use of a configuration of a joint transform correlator

Applied Optics   42 ( 8 ) 1508 - 1514   2003

DOI

Measurement of Out-of-Plane Displacement Using Phase-Shifting Digital Holography

TAKAHASHI Isao, MORIMOTO Yoshiharu, NOMURA Takanori, YONEYAMA Satoru, FUJIGAKI Motoharu

Journal of JSEM ( 日本実験力学会 )  3 ( 2 ) 98 - 102   2003

DOI

Deformation measurement by digital holographic, interferometry

Takahashi, I, T Nomura, Y Morimoto, S Yoneyama, M Fujigaki

OPTOMECHATRONIC SYSTEMS IV ( SPIE-INT SOC OPTICAL ENGINEERING )  5264   206 - 213   2003

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Deformation measurement of a cantilever based on digital holographic interferometry is presented. The digital holo,,, rams of the cantilever before and after deformation are obtained by use of phase-shifting technique. By using the phase-shifting digital holography. the object wave information without zeroth order diffraction wave can be extracted. The phase difference of the reconstructed cantilever before and after deformation is obtained numerically using discrete Fresnel diffraction integral. Owing to the numerical analysis, the deformation of the cantilever can be obtained with high resolution of nanometer dimensions. The optical experimental results are shown to confirm our proposed method. Furthermore, we propose a mechanical movement free double-exposure method in phase-shifting digital holography using a laser diode.

DOI

Thermal Deformation Measurement by Two-directional Integrated Phase-shifting Moire Interferometry

YAMAMOTO Yuko, MORIMOTO Yoshiharu, NOMURA Takanori, FUJIGAKI Motoharu, YONEYAMA Satoru

Proceedings of JSEM ( 日本実験力学会 )  2   27 - 31   2002.08

Optical Information Processing

NOMURA Takanori

光学   31 ( 5 ) 399 - 399   2002.05

Secure optical storage with a random phase key code based on a joint transform correlator architecture

T Nomura, S Mikan, Y Morimoto, B Javidi

ALGORITHMS AND SYSTEMS FOR OPTICAL INFORMATION PROCESSING VI ( SPIE-INT SOC OPTICAL ENGINEERING )  4789   275 - 282   2002

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An encrypted optical storage based on a joint transform correlator architecture by using a photorefractive material is presented. A key code designed by optimized algorithm so that its Fourier transform has a uniform amplitude distribution and a random phase distribution is introduced. Original two-dimensional data and the key code are placed side by side at the input plane. Both of them are stored in a photorefractive material as a joint power spectrum. The retrieval of the original data can be achieved with the same key code. We can record multiple two-dimensional data in a same crystal by angular multiplexing. Furthermore we can record by key code multiplexing because another designed key code can produce another independent phase distribution. We demonstrate the concept of the optical data storage system by computer simulations.