Misc - 野村　孝徳

Compressive spectral imaging with a blazed grating to improve the signal-to-noise ratio

Daiki Shimoyama, Yusuke Saita, and Takanori Nomura,

OSJ-OSA-OSK Joint Symposia on Optics Program     2020年11月

Coaxial holographic memory to increase recording capacity using computer-generated hologram

Takanori Nomura, Naru Yoneda, and Yusuke Saita, (担当区分： 筆頭著者,　責任著者 )

International Conference on Optoelectronic and Microelectronic Technology and Application 2020     2020年10月  [招待有り]

Simultaneous measurement of two parameters of the spherical lens by low-coherence interferometry

Ying Sun, Takanori Nomura

Proceedings of SPIE - The International Society for Optical Engineering ( SPIE-INT SOC OPTICAL ENGINEERING )  11548   2020年  [査読有り]

　概要を見る

To measure different parameters of a spherical lens simultaneously, a method by low-coherence interferometry with a low temporal coherent light source is proposed. This proposed method can obtain both the radius of curvature and the central thickness of a spherical lens in a single optical system. Owing to the property of low temporal coherence, the contrast of interference fringe pattern, hologram, varies with the optical path difference of an object beam and a reference beam. This enables the central thickness of the test lens to acquire with a Michelson interferometer. Simultaneously, the spherical shape of the test lens, namely the radius of curvature, can be obtained from a hologram which contains information of the wavefront curvature from the reected beam of the spherical surface of the test lens.

DOI

Numerical evaluation of transport-of-intensity phase imaging with oblique illumination for refractive index tomography

Koshi Komuro, Yusuke Saita, Yosuke Tamada, Takanori Nomura

Proceedings Digital Holography and Three-Dimensional Imaging 2019     2019年05月  [査読有り]

　概要を見る

A scanless phase retrieval method based on the transport of intensity equation is proposed for refractive index tomography. A phase distribution is measured from defocused intensity distributions obtained with oblique illumination of different tilt angles.

DOI

Computer-generated-hologram-based holographic data storage using a transport of intensity equation

Naru Yoneda, Yusuke Saita, Koshi Komuro, Teruyoshi Nobukawa, Takanori Nomura

Optics InfoBase Conference Papers   Part F125-OPJ 2018   2018年  [査読有り]

　概要を見る

Utilization of phase information can increase the recording density of holographic data storage. In this paper, a transport of intensity equation is introduced to computer-generated-hologram-based holographic data storage, which can obtain the phase datapage while keeping an optical setup simple and compact. Moreover, two defocused intensity distributions for the transport of intensity equation can be simultaneously obtained by using a conjugate beam from the computer-generated hologram.

DOI

Deep-learning-based phase retrieval for pure phase objects in computational ghost imaging

Koshi Komuro, Alexandre Goy, Takanori Nomura, George Barbastathis

Optics InfoBase Conference Papers   Part F125-OPJ 2018   2018年  [査読有り]

　概要を見る

A deep-learning-based phase retrieval method is proposed for computational ghost imaging (CGI). In the method, a defocused intensity distribution of an object is obtained by the CGI. An object's phase distribution is retrieved from the intensity distribution by a trained deep neural network. The advantage of the method is that the phase retrieval can be achieved with a low signal to noise ratio. The effects of noise level and defocus distance are investigated.

DOI

カラー撮像素子を用いた3バンド像面フーリエ分光映像法

谷口 祐太, 野村 孝徳

応用物理学会学術講演会講演予稿集 ( 公益社団法人 応用物理学会 )  2016.2   741 - 741   2016年09月

DOI

ホログラフィックディスプレイにおけるスペックル低減法 (「ホログラフィによる立体テレビ技術の現状と展望」特集号)

森 裕, 野村 孝徳

レーザー研究 = The review of laser engineering : レーザー学会誌 ( レーザー学会 )  44 ( 7 ) 429 - 433   2016年07月

ディジタルホログラフィーの高画質化を目指したホログラム合成技術

野村 孝徳

光学 ( 応用物理学会分科会日本光学会 )  40 ( 10 ) 539 - 543   2011年10月

Optical reconstruction of digital hologram using spatial light modulator for binocular stereopsis

MORI Yutaka, NOMURA Takanori

Digital Holography and Three-Dimensional Imaging 2011     paper DTuC7   2011年05月  [査読有り]

DOI

Digital holographic binocular stereopsis

NOMURA Takanori, MORI Yutaka

Digital Holography and Three-Dimensional Imaging 2010     DWB5   2010年04月  [査読有り]

DOI

Object recognition by use of polarimetric phase-shifting digital holography

Takanori Nomura, Bahram Javidi

OPTICS LETTERS ( OPTICAL SOC AMER )  32 ( 15 ) 2146 - 2148   2007年08月  [査読有り]

　概要を見る

Pattern recognition by use of polarimetric phase-shifting digital holography is presented. Using holography, the amplitude distribution and phase difference distribution between two orthogonal polarizations of three-dimensional (3D) or two-dimensional phase objects are obtained. This information contains both complex amplitude and polarimetric characteristics of the object, and it can be used for improving the discrimination capability of object recognition. Experimental results are presented to demonstrate the idea. To the best of our knowledge, this is the first report on 3D polarimetric recognition of objects using digital holography. (C) 2007 Optical Society of America.

DOI

「3次元情報のディジタル記録・再生-ディジタルホログラフィの最前線-」解説小特集号によせて

野村 孝徳

レーザー研究   35 ( 6 ) 357 - 357   2007年06月

波面分割位相シフトディジタルホログラフィ

野村 孝徳, 村田 新治, 米山 聡, 似内 映之, 沼田 卓久

レーザー研究 ( レ-ザ-学会 )  35 ( 6 ) 363 - 367   2007年06月

Polarization imaging of a 3D object by use of on-axis phase-shifting digital holography

Takanori Nomura, Bahram Javidi, Shinji Murata, Eiji Nitanai, Takuhisa Numata

OPTICS LETTERS ( OPTICAL SOC AMER )  32 ( 5 ) 481 - 483   2007年03月  [査読有り]

　概要を見る

A polarimetric imaging method of a 3D object by use of on-axis phase-shifting digital holography is presented. The polarimetric image results from a combination of two kinds of holographic imaging using orthogonal polarized reference waves. Experimental demonstration of a 3D polarimetric imaging is presented. (c) 2007 Optical Society of America.

DOI

Multi-Spectral Holographic Three-Dimensional Image Fusion Using Discrete Wavelet Transform

Bahram Javidi, Cuong Manh Do, Seung-Hyun Hong, Takanori Nomura

JOURNAL OF DISPLAY TECHNOLOGY ( IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC )  2 ( 4 ) 411 - 417   2006年12月  [査読有り]

　概要を見る

We present multi-spectral holographic three-dimensional image fusion using the discrete wavelet transform (DWT). The fusion results are compared with those of the Gaussian and Laplacian pyramid fusion methods. The advantage of the DWT over other methods is that it has more flexibility in controlling high frequency components as well as low frequency components, which improves the fused image quality. A wavelength tunable solid-state pumped laser is used to record up to 11 holograms with wavelengths from 567 to 613 nm. We present the fused reconstructed holographic images including multi-spectral fused images from the recorded multiple holograms. Fused multi-wavelength reconstructed holographic images provide multi-spectral information about the objects.

DOI

Design of input phase mask for the space bandwidth of the optical encryption system

T Nomura, E Nitanai, T Numata, B Javidi

OPTICAL ENGINEERING ( SPIE-INT SOCIETY OPTICAL ENGINEERING )  45 ( 1 )   2006年01月

　概要を見る

A method to design an input phase mask for double-random phase-encoding optical encryption 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 correspond 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 phase levels of the designed input phase mask. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

DOI

Phase-shifting digital holography with a phase difference between orthogonal polarizations

Appl. Opt

Takanori Nomura, Shinji Murata, Eiji Nitanai, and Takuhisa Numata   45 ( 20 ) 4873 - 4877   2006年

DOI

Image reconstruction from compressed encrypted digital hologram

T Nomura, A Okazaki, M Kameda, Y Morimoto, B Javidi

OPTICAL ENGINEERING ( SPIE-INT SOCIETY OPTICAL ENGINEERING )  44 ( 7 )   2005年07月

　概要を見る

An encrypted digital holographic data reconstruction method with data compression is proposed. We show that the number of quantization levels of the digital hologram can be reduced. By computer simulations, we confirm that the method is especially useful for binary images. For gray-scale images, we propose a bit plane decomposition method. By this method, we show that both high reconstructed image quality and a high compression ratio can be achieved. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

DOI

Hybrid optical encryption of a three-dimensional object

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