研究者データベース

岡本 淳(オカモト アツシ)
情報科学研究院 情報エレクトロニクス部門 先端エレクトロニクス分野
准教授

基本情報

所属

  • 情報科学研究院 情報エレクトロニクス部門 先端エレクトロニクス分野

職名

  • 准教授

学位

  • 工学博士(北海道大学)
  • 工学修士(北海道大学)

ホームページURL

J-Global ID

研究キーワード

  • フォトリフラクティブ効果   ホログラフィ   光情報処理   情報光学   光衛星間通信   光通信   位相共役光学   非線形光学   光エレクトロニクス   光インターコネクション   光記録   光メモリ   Optical intersatelite communication   Optical communication   Phase Conjutation   Nonlinear Optics   Optoelectronics   Self organization   Optical interconnection   Holographic memory   Optical storage   Optical memory   

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 通信工学
  • ものづくり技術(機械・電気電子・化学工学) / 電子デバイス、電子機器
  • ナノテク・材料 / 光工学、光量子科学

職歴

  • 2007年 - 北海道大学准教授(情報科学研究科先端エレクトロニクス講座) 准教授

所属学協会

  • 電子情報通信学会   日本光学会   The Optical Society of America(OSA)   Optical Society of Japan   IEICE(The Institute of Electronics, Information and Communication Engineers)   

研究活動情報

論文

  • Virtual phase conjugation based optical tomography for single-shot three-dimensional imaging
    Yuta Goto, Atsushi Okamoto, Atsushi Shibukawa, Kazuhisa Ogawa, Akihisa Tomita
    Optics Express 26 4 3779 - 3790 2018年02月 [査読有り][通常論文]
  • Shimpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Naoya Wada
    Applied Optics 57 2 146 - 153 2018年01月10日 [査読有り][通常論文]
     
    Volume holographic demultiplexers (VHDMs) provide spatial mode demultiplexing using simple optical systems. However, applying VHDM to practical optical communication systems is difficult, as typical holographic media have no sensitivity in the infrared region, which includes optical transmission bands. In this paper, we propose a VHDM scheme combined with a dual-wavelength method (DWM). Using the DWM, VHDMs are able to perform mode demultiplexing in the optical transmission bands. We experimentally demonstrated the basic operation of our proposal using experiments performed at an 850-nm wavelength. In addition, we performed numerical simulations to investigate the application of VHDM to the C-band.
  • Shimpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Naoya Wada
    22nd Microoptics Conference, MOC 2017 2017- P-62 260 - 261 2018年01月02日 [査読有り][通常論文]
     
    We demonstrated the mode-group demultiplexing technique based on a volume holographic demultiplexer (VHDM) for mode-group division multiplexing transmission using multi-mode fibers. In the experiment, the VHDM achieved the separating of three mode-group channels with a single holographic recording medium. Thus, the modal cross-talk was obtained as -14.7 dB.
  • Yuta Goto, Atsushi Okamoto, Kazuhisa Ogawa, Akihisa Tomita
    22nd Microoptics Conference, MOC 2017 2017- PD5 358 - 359 2018年01月02日 [査読有り][通常論文]
     
    We propose virtual-phase-conjugation based optical tomography (VPC-OT) incorporated with the compensation of the optical aberration for improving the imaging quality. The compensation scheme is implemented by optically measuring the transmission function of the beam propagation. Then, we confirmed that this scheme greatly improves the signal level of VPC-OT.
  • Tomohiro Maeda, Atsushi Okamoto, Kazuhisa Ogawa, Akihisa Tomita, Yuta Wakayama, Takehiro Tsuritani
    22nd Microoptics Conference, MOC 2017 2017- C-4 68 - 69 2018年01月02日 [査読有り][通常論文]
     
    We propose a selective mode conversion method using dual-phase modulation which performs the full-complex amplitude modulation by use of two phase-type spatial light modulators. In the experiment, the crosstalk to undesired spatial mode was supressed less than -21.2 dB for the 4-LP modes of a few-mode fiber.
  • Selective spatial mode attenuator using phase-intensity-phase modulation toward mode-division multiplexing transmission
    Zihan Zhou, Atsushi Okamoto, Shimpei Shimizu, Kazuhisa Ogawa, Akihisa Tomita, Yuta Wakayama, Takehiro Tsuritani
    SPIE Photonics West 2018 (PW2018) 10561-15 2018年 [査読有り][通常論文]
  • Measurement of differential mode delay using reference-free low-coherence digital holography
    Shogo Hoshino, Atsushi Okamoto, Yuta Goto, Kazuhisa Ogawa, Akihisa Tomita, Yuta Wakayama, Takehiro Tsuritani
    SPIE Photonics West 2018 (PW2018) 10561-12 2018年 [査読有り][通常論文]
  • Kosuke Fukui, Akihisa Tomita, Atsushi Okamoto
    PHYSICAL REVIEW LETTERS 119 18 180507-1 - 180507-4 2017年11月 [査読有り][通常論文]
     
    To implement fault-tolerant quantum computation with continuous variables, Gottesman-Kitaev-Preskill (GKP) qubits have been recognized as an important technological element. However, the analog outcome of GKP qubits, which includes beneficial information to improve the error tolerance, has been wasted, because the GKP qubits have been treated as only discrete variables. In this Letter, we propose a hybrid quantum error correction approach that combines digital information with the analog information of the GKP qubits using a maximum-likelihood method. As an example, we demonstrate that the three-qubit bit-flip code can correct double errors, whereas the conventional method based on majority voting on the binary measurement outcome can correct only a single error. As another example, we show that a concatenated code known as Knill's C-4/C-6 code can achieve the hashing bound for the quantum capacity of the Gaussian quantum channel (GQC). To the best of our knowledge, this approach is the first attempt to draw both digital and analog information to improve quantum error correction performance and achieve the hashing bound for the quantum capacity of the GQC.
  • Spatial mode demultiplexing technique using angularly multiplexed volume holograms with a phase plate
    Shimpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Naoya Wada
    Japanese Journal of Applied Physics 56 98 09NA05-1 - 09NA05-5 2017年08月 [査読有り][通常論文]
  • Improvement of Conversion Accuracy in Volume Holographic Mode-Demultiplexing Converter Using Shaped Beams
    Fumiya Mizukawa, Atsushi Okamoto, Yuta Goto, Shimpei Shimizu, Kazuhisa Ogawa, Akihisa Tomita
    International Workshop on Holography and Related Technologies 2017 (IWH2017) P2 2017年 [査読有り][通常論文]
  • Design of Complex Amplitude Modulation for Suppressing Optical Loss in Mode Conversion by Considering Radiation Modes
    Tomohiro Maeda, Atsushi Okamoto, Kazuhisa Ogawa, Akihisa Tomita
    International Workshop on Holography and Related Technologies 2017 (IWH2017) P9 2017年 [査読有り][通常論文]
  • Multiplexing and Demultiplexing of Digital Images using Virtual Phase Conjugation for High-Density Holographic Data Storage
    Yuta Goto, Atsushi Okamoto, Kazuhisa Ogawa, Akihisa Tomita
    International Workshop on Holography and Related Technologies 2017 (IWH2017) P10 2017年 [査読有り][通常論文]
  • Spatial Mode Separation and Conversion Technique Using Volume Hologram with a Random Optical Diffuser
    Fumiya Mizukawa, Atsushi Okamoto, Yuta Goto, Shimpei Shimizu, Kazuhisa Ogawa, Akihisa Tomita
    27th International Symposium on Imaging, Sensing, and Optical Memory 2017 (ISOM’17) Tu-J-35 2017年 [査読有り][通常論文]
  • Experiment on Spatial Mode Demultiplexing Technique Using Cascaded Volume Hologram
    Shimpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Naoya Wada
    27th International Symposium on Imaging, Sensing, and Optical Memory 2017 (ISOM’17) Tu-J-25 2017年 [査読有り][通常論文]
  • Multiplexing Technique using Virtual Phase Conjugation for High-Density Holographic Data Storage Systems
    Yuta Goto, Atsushi Okamoto, Masanori Takabayashi, Akihisa Tomita
    27th International Symposium on Imaging, Sensing, and Optical Memory 2017 (ISOM’17) Tu-PP-02 2017年 [査読有り][通常論文]
  • Optimization of Volume Holographic Spatial Mode Demultiplexer with a Phase Plate Using Simulated Annealing
    Shimpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Naoya Wada
    International Workshop on Holography and Related Technologies 2017 (IWH2017) 23a3 2017年 [査読有り][通常論文]
  • Experiment on spatial mode separation and conversion technique using volume hologram
    Fumiya Mizukawa, Atsushi Okamoto, Yuta Goto, Shimpei Shimizu, Kazuhisa Ogawa, Akihisa Tomita
    7th EOS Topical Meeting on Optical Microsystems (OµS’17) 35 2017年 [査読有り][通常論文]
  • Experiment on spatial mode demultiplexer based on angularly multiplexed volume hologram at 850 nm wavelength with dual-wavelength method
    himpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Naoya Wada
    7th EOS Topical Meeting on Optical Microsystems (OµS’17) 22 2017年 [査読有り][通常論文]
  • Depth-resolution characterization of optical tomography using virtual phase conjugation
    Yuta Goto, Atsushi Okamoto, Atsushi Shibukawa, Kazuhisa Ogawa, Akihisa Tomita, Kunihiro Sato
    7th EOS Topical Meeting on Optical Microsystems (OµS’17) 5 2017年 [査読有り][通常論文]
  • Kensuke Nakata, Akihisa Tomita, Mikio Fujiwara, Ken-ichiro Yoshino, Akio Tajima, Atsushi Okamoto, Kazuhisa Ogawa
    OPTICS EXPRESS 25 2 622 - 634 2017年01月 [査読有り][通常論文]
     
    Security certification of quantum key distribution (QKD) systems under practical conditions is necessary for social deployment. This article focused on the transmitter, and, in particular, investigated the intensity fluctuation of the optical pulses emitted by a gain-switched semiconductor laser used in QKD systems implementing decoy-BB84 protocol. A large intensity fluctuation was observed for low excitation, showing strong negative correlation between the adjacent pulses, which would affect the final key rate. The fluctuation decreased and the correlation disappeared as excitation increased. Simulation with rate equations successfully reproduced the experimental results and revealed that the large fluctuation originates from an intrinsic instability of gain-switched lasers driven periodically at a rate comparable to the inverse of carrier lifetime, as in GHz-clock QKD systems. Methods for further reduction of the intensity fluctuation were also discussed. (C) 2017 Optical Society of America
  • Multi-Layered Holographic Memory using Virtual Phase Conjugation
    Yuta Goto, Atsushi Okamoto, Kazuhisa Ogawa, Akihisa Tomita, Kunihiro Sato
    Technical Digest of the International Workshop on Holography 2016 (IWH 2016) 60  2016年11月 [査読有り][通常論文]
  • Phase measurement of a tilted plane mirror using the derivative estimation of a single hologram
    Jin Nozawa, Atsuhshi Okamoto, Yasuyuki Kuno, Masataka Toda, Kazuhisa Ogawa, Akihisa Tomita
    Technical Digest of the International Workshop on Holography 2016 (IWH 2016) 17  2016年11月 [査読有り][通常論文]
  • Performance Evaluation of High Speed Full Motion Simulator for Holographic Memory Based on 3D FFT-BPM with GPU Acceleration
    Hisatoshi Funakoshi, Atsushi Okamoto, Satoshi Honma
    Technical Digest of International Symposium on Optical Memory 2016 (ISOM 2016) Tu-J-03 2016年10月 [査読有り][通常論文]
  • Accuracy evaluation of phase shifting digital holography using virtual interferogram-generation algorithm
    Jin Nozawa, Atsuhshi Okamoto, Kazuhisa Ogawa, Akihisa Tomita, Kunihiro Sato
    Technical Digest of International Symposium on Optical Memory 2016 (ISOM 2016) Tu-J-17 2016年10月 [査読有り][通常論文]
  • Multiplexing Technique using Virtual Phase Conjugation for High-Density Holographic Data Storage Systems
    岡本 淳
    Yuta Goto, Atsushi Okamoto, Masanori Takabayashi, and Akihisa Tomita We-L-03 2016年10月 [査読有り][通常論文]
  • Spatial Mode Separation and Interconversion Using Volume Hologram
    Fumiya Mizukawa, Atsushi Okamoto, Yuta Goto, Shimpei Shimizu, Satoshi Honma, Kazuhisa Ogawa, Akihisa Tomita
    Technical Digest of International Symposium on Optical Memory 2016 (ISOM 2016) Tu-I-04 2016年10月 [査読有り][通常論文]
  • Effective Mode Demultiplexing Technique Using Angularly Multiplexed Volume Holograms with a Phase Plate
    Shimpei Shimizu, Atsushi Okamoto, Fumiya Mizukawa, Taketoshi Takahata, Shusaku Noda, Naoya Wada, Kazuhisa Ogawa, Akihisa Tomita
    Technical Digest of International Symposium on Optical Memory 2016 (ISOM 2016) Tu-I-03 2016年10月 [査読有り][通常論文]
  • Yuta Goto, Atsushi Okamoto, Yuta Wakayama, Kazuhisa Ogawa, Jin Nozawa, Akihisa Tomita, Takehiro Tsuritani
    OPTICS EXPRESS 24 21 24739 - 24749 2016年10月 [査読有り][通常論文]
     
    To obtain a phase distribution without the use of an optical path besides an object beam, a reference-free holographic diversity interferometry (RF-HDI) has been proposed. Although the RF-HDI can generate an internal reference beam from the object beam, the method has a problem of measurement accuracy due to insufficient power of the internal reference beam. To solve the problem, we newly propose a RF-HDI via iterative measurements. Our method improves the measurement accuracy by utilizing iterative measurements and feedback of each obtained phase image to the measurement system. In the experiment, the phase image, which has a random pattern, can be measured as an object beam with a higher accuracy than in the conventional RF-HDI. To support this result, we also evaluated the wavefront accuracy and optical power efficiency of an internal reference beam in this method. As a result, we verified that our method enables us to generate an internal reference beam that has the wavefront of a near single plane wave and a higher power efficiency than the conventional RF-HDI. In addition, our method can be applied to measurement for the modal content in an optical fiber, atmosphere turbulence, etc., where it is difficult to prepare an external reference beam with a high coherency. (C) 2016 Optical Society of America
  • Taisuke Eto, Masanori Takabayashi, Atsushi Okamoto, Masatoshi Bunsen, Takashi Okamoto
    JAPANESE JOURNAL OF APPLIED PHYSICS 55 8 08RD01.1 - 08RD01.7 2016年08月 [査読有り][通常論文]
     
    A three-dimensional (3D) shift multiplexing technique is applied to increase the number of multiplexed datapages in self-referential holographic data storage (SR-HDS), enabling holographic recording with purely one-beam geometry. In the 3D shift multiplexing technique, the recording medium is shifted not only along the x-and y-axes but also along the z-axis to multiplex the datapages. Because the shift directions in the 3D shift multiplexing technique are expanded compared with the conventional 2D technique, the number of multiplexed datapages is expected to be increased. We numerically clarify the appropriate 3D recording layout of holograms in which the effect of the inter-page crosstalk can be reduced after showing that datapages are multiplexed on shifting the recording medium along the z-axis. The results show 3D shift multiplexing can effectively realize high-density SR-HDS when appropriately designed layouts are used. (C) 2016 The Japan Society of Applied Physics.
  • Yuta Goto, Atsushi Okamoto, Masataka Toda, Yasuyuki Kuno, Jin Nozawa, Kazuhisa Ogawa, Akihisa Tomita
    JAPANESE JOURNAL OF APPLIED PHYSICS 55 8 08RE04.1 - 08RE04.6 2016年08月 [査読有り][通常論文]
     
    We propose a digital confocal microscope using a virtual 4f-system based on numerical beam propagation for depth measurement without mechanical scanning. In our technique, the information in the sample target along the depth direction is obtained by defocusing the virtual 4f-system, which consists of two virtual lenses arranged in a computer simulation. The principle of our technique is completely different from that of the mechanical scanning method used in the conventional confocal microscope based on digital holography. By using the virtual 4f-system, the measurement and exposure time can be markedly reduced because multilayered tomographic images are generated using a single measurement. In this study, we tested the virtual depth imaging technique by measuring cover glasses arranged along the depth direction. (C) 2016 The Japan Society of Applied Physics
  • Fumiaki Matsuoka, Akihisa Tomita, Atsushi Okamoto
    Physical Review A 93 032308  2016年 [査読有り][通常論文]
  • Jin Nozawa, Atsushi Okamoto, Atsushi Shibukawa, Masanori Takabayashi, Akihisa Tomita
    APPLIED OPTICS 54 29 8644 - 8652 2015年10月 [査読有り][通常論文]
     
    We propose a two-channel holographic diversity interferometer (2ch-HDI) system for single-shot and highly accurate measurements of complex amplitude fields with a simple optical setup. In this method, two phase-shifted interference patterns are generated, without requiring a phase-shifting device, by entering a circularly polarized reference beam into a polarizing beam splitter, and the resulting patterns are captured simultaneously using two image sensors. However, differences in the intensity distributions of the two image sensors may lead to serious measurement errors. Thus, we also develop a two-channel algorithm optimized for the 2ch-HDI to compensate for these differences. Simulation results show that this algorithm can compensate for such differences in the intensity distributions in the two image sensors. Experimental results confirm that the combination of the 2ch-HDI and the calculation algorithm significantly enhances measurement accuracy. (c) 2015 Optical Society of America
  • Masanori Takabayashi, Atsushi Okamoto, Taisuke Eto, Takashi Okamoto
    APPLIED OPTICS 54 16 5167 - 5174 2015年06月 [査読有り][通常論文]
     
    Two methods are proposed to improve the readout quality of signals in self-referential holographic data storage (SR-HDS), in which no reference beam is required to record and read digital data holographically: the off-the-focus (OtF) method and the oversampling additional pattern (OsAP) method. The focal point is located outside of the recording medium in the OtF method, and the signal pattern is recorded with an additional pattern that possesses a higher spatial frequency than the signal pattern in the OsAP method. Experimental results show that both methods are effective for drastically improving the signal-to-noise ratio (SNR). In addition, through numerical simulation, it can be observed that the readout quality is improved by the achievement of homogeneous hologram distribution. (C) 2015 Optical Society of America
  • NISHIMAKI Kaori, OKAMOTO Atsushi, SHIBUKAWA Atsushi, TAKABAYASHI Masanori, TOMITA Akihisa, TAKAYAMA Yoshihisa
    Opt Rev 21 3 415 - 424 2014年06月 [査読有り][通常論文]
  • Atsushi Shibukawa, Atsushi Okamoto, Yuta Goto, Satoshi Honma, Akihisa Tomita
    OPTICS EXPRESS 22 10 11918 - 11929 2014年05月 [査読有り][通常論文]
     
    In a conventional digital phase conjugation system, only the phase of an input light is time-reversed. This deteriorates phase conjugation fidelity and restricts application fields to specific cases only when the input light has uniformly-distributed scattered wavefront. To overcome these difficulties, we present a digital phase conjugate mirror based on parallel alignment of two phase-only spatial light modulators (SLMs), in which both amplitude and phase of the input light can be time-reversed. Experimental result showed that, in the phase conjugation through a holographic diffuser with diffusion angle of 0.5 degree, background noises decrease to 65% by our digital phase conjugation mirror. (C)2014 Optical Society of America
  • Atsushi Shibukawa, Atsushi Okamoto, Masanori Takabayashi, Akihisa Tomita
    OPTICS EXPRESS 22 4 3968 - 3982 2014年02月 [査読有り][通常論文]
     
    We propose a spatial cross modulation method using a random diffuser and a phase-only spatial light modulator (SLM), by which arbitrary complex-amplitude fields can be generated with higher spatial resolution and diffraction efficiency than off-axis and double-phase computer-generated holograms. Our method encodes the original complex object as a phase-only diffusion image by scattering the complex object using a random diffuser. In addition, all incoming light to the SLM is consumed for a single diffraction order, making a diffraction efficiency of more than 90% possible. This method can be applied for holographic data storage, three-dimensional displays, and other such applications. (C) 2014 Optical Society of America
  • Keisuke Zukeran, Atsushi Okamoto, Masanori Takabayashi, Atsushi Shibukawa, Kunihiro Sato, Akihisa Tomita
    JAPANESE JOURNAL OF APPLIED PHYSICS 52 9 09LD13.1-09LD13.9  2013年09月 [査読有り][通常論文]
     
    We proposed a double-referential holography (DRH) that allows phase-detection without external additional beams. In the DRH, phantom beams, prepared in the same optical path as signal beams and preliminary multiplexed in a recording medium along with the signal, are used to produce interference fringes on an imager for converting a phase into an intensity distribution. The DRH enables stable and high-accuracy phase detection independent of the fluctuations and vibrations of the optical system owing to medium shift and temperature variation. Besides, the collinear arrangement of the signal and phantom beams leads to the compactness of the optical data storage system. We conducted an experiment using binary phase modulation signals for verifying the DRH operation. In addition, 38-level spatial quadrature amplitude modulation signals were successfully reproduced with the DRH by numerical simulation. Furthermore, we verified that the distributed phase-shifting method moderates the dynamic range consumption for the exposure of phantom beams. (c) 2013 The Japan Society of Applied Physics
  • Masatoshi Bunsen, Shuhei Umetsu, Masanori Takabayashi, Atsushi Okamoto
    JAPANESE JOURNAL OF APPLIED PHYSICS 52 9 09LD04.1-09LD04.5  2013年09月 [査読有り][通常論文]
     
    A technique for the phase and amplitude detection of object beams with multivalued phase and amplitude modulation is proposed for holographic storage systems. Generally, the spatial distribution of the complex amplitude of the object beam can be precisely detected by phase-shifting interferometric measurements in which the phase of the reference wave for interferometry is temporally or spatially changed in the datapage retrieval process. On the other hand, our technique allows fast, accurate, and feasible phase and amplitude demodulations by preliminary embedding phase shift into the phase signal of the datapage during recording. This technique will significantly improve the data transfer rate and vibration tolerance of the holographic storage system because the complex amplitudes of the object beam carrying datapages can be detected by single-shot image capturing. The optical system for datapage replay will also be simplified because there is no need to use any phase-shifting device during data retrieval. The single-shot detection of the phase-modulated datapage is experimentally demonstrated. (c) 2013 The Japan Society of Applied Physics
  • Atsushi Shibukawa, Atsushi Okamoto, Yuta Wakayama, Akihisa Tomita, Hisatoshi Funakoshi, Kunihiro Sato
    JAPANESE JOURNAL OF APPLIED PHYSICS 52 9 09LD03.1-09LD03.9  2013年09月 [査読有り][通常論文]
     
    To suppress interpage crosstalk that strongly restricts holographic data storage capacity, a digital image diffusion technique was proposed. In this technique, signal and crosstalk components are separated from the propagation angle difference produced by using a random diffuser and the nature of phase conjugate lights. The most attractive feature of the technique is that crosstalk suppression can be conducted while mostly keeping the conventional holographic data storage system unchanged by integrating optical processing and digital processing effectively. The connection between the two types of processing is realized by using two spatial light modulators for complex amplitude generation and phase detection methods for complex amplitude measurement. The simulation results showed that the proposed technique could increase the recording density 5.5-fold and reduce the shift pitch by a factor of 5 in comparison with conventional multiplexing methods when the diffusion angle of the diffuser is 10 degrees. (c) 2013 The Japan Society of Applied Physics
  • Fumiaki Matsuoka, Akihisa Tomita, Atsushi Okamoto
    Physical Review A - Atomic, Molecular, and Optical Physics 88 2 022313.1-022313.7  2013年08月12日 [査読有り][通常論文]
     
    In order to improve the error probability of generating entanglement by communication for quantum computation, we propose the use of squeezed light. When generating entanglement between two atoms by communication, the error probability can be reduced by increasing the distance between quantum states of probe light in phase space. The phase rotation of light depends on the atom-photon coupling strength and the light amplitude, which are limited in practice. A large error probability has been expected for coherent probe light. If we assume typical values of light amplitude and phase rotation, α=100 and θ=0.01, the error probability is estimated to be Pcoh(min)=0.14 and Pcoh(hom)=0.23 for minimum error discrimination and homodyne measurements. The error probability can be reduced to Psqu(min)=1.73×10-8 and Psqu(hom)=4.09×10-5 using squeezed coherent light, where the same values of the mean photon number and the phase rotation angle are assumed for the coherent light probe. These values satisfy the requirements for scalable quantum computation. © 2013 American Physical Society.
  • Yuta Wakayama, Atsushi Okamoto, Kento Kawabata, Akihisa Tomita, Kunihiro Sato
    OPTICS EXPRESS 21 10 12920 - 12933 2013年05月 [査読有り][通常論文]
     
    This study proposes a volume holographic demultiplexer (VHDM) for extracting the spatial modes excited in a multimode fiber. A unique feature of the demultiplexer is that it can separate a number of multiplexed modes output from a fiber in different directions by using multi-recorded holograms without beam splitters, which results in a simple configuration as compared with that using phase plates instead of holograms. In this study, an experiment is conducted to demonstrate the basic operations for three LP mode groups to confirm the performance of the proposed VHDM and to estimate the signal-to-crosstalk noise ratio (SNR). As a result, an SNR of greater than 20 dB is obtained. (C) 2013 Optical Society of America
  • Kohei Aoki, Atsushi Okamoto, Yuta Wakayama, Akihisa Tomita, Satoshi Honma
    Optics Letters 38 5 769 - 771 2013年03月01日 [査読有り][通常論文]
     
    We propose a mode multiplexer based on volume holograms to realize a simple and efficient mode-division-multiplexed transmission system that supports a large number of modes. Selective multiexcitation of three spatial modes into a conventional multimode fiber is experimentally demonstrated. This device could potentially multiplex 10 or more modes. Future perspectives of the mode multiplexer for application in mode-division multiplexing are also discussed. © 2013 Optical Society of America.
  • Masanori Takabayashi, Atsushi Okamoto
    OPTICS EXPRESS 21 3 3669 - 3681 2013年02月 [査読有り][通常論文]
     
    Holographic recording methods require the use of a reference beam that is coherent with the signal beam carrying the information to be recorded. In this paper, we propose self-referential holography (SRH) for holographic recording without the use of a reference beam. SRH can realize purely one-beam holographic recording by considering the signal beam itself as the reference beam. The readout process in SRH is based on energy transfer by inter-pixel interference in holographic diffraction, which depends on the spatial phase difference between the recorded phase and the readout phase. The phase-modulated recorded signal is converted into an intensity-modulated beam that can be easily detected using a conventional image sensor. SRH can be used effectively for holographic data storage and phase-to-intensity conversion. (C) 2013 Optical Society of America
  • KAWABATA Kento, OKAMOTO Atsushi, HONMA Satoshi, WAKAYAMA Yuta, SATO Kunihiro, TOMITA Akihisa
    Proc SPIE 8647 86470C.1-86470C.7  2013年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto
    OPTICAL AND QUANTUM ELECTRONICS 44 3-5 265 - 271 2012年06月 [査読有り][通常論文]
     
    We have demonstrated that light is confined in a single mode near a very small defect (such as an impurity atom) embedded in photonic crystals by coherent control using a dark line that is a spectrum singularity leading to the complete quenching of emission. In this demonstration, we have clarified the strong confinement and a very short response time, as compared with the widely used tunable PBG method. These features are useful for keeping the memory in a two-state quantum system such as a quantum bit (qubit) and for processing quantum information.
  • AOKI Kohei, OKAMOTO Atsushi, ODA Takuya, WAKAYAMA Yuta, TOMITA Akihisa
    Tech Dig Int Conf Opt photonics Des Fabr 8th 41 - 42 2012年 [査読有り][通常論文]
  • Masanori Takabayashi, Atsushi Okamoto, Akihisa Tomita, Masatoshi Bunsen
    JAPANESE JOURNAL OF APPLIED PHYSICS 50 9 09ME05.1-09ME05.5  2011年09月 [査読有り][通常論文]
     
    For the purpose of increasing the data density of holographic memories, we propose a novel signal modulation method named hybrid modulation method, which is a combination of multi level phase-modulated signals and intensity-modulated signals. As a first step, we show that the data density of holographic data storage is mainly determined by multiplexing numbers and by coding efficiency in input signals. In this study, we focus on increasing coding efficiency using the hybrid modulation method. From the results of recording and reading simulations based on the fast-Fourier transform beam propagation method, the hybrid modulation method achieves approximately 2 times higher data density than the conventional methods of two-level phase-only modulation and two-level intensity-only modulation. (C) 2011 The Japan Society of Applied Physics
  • Atsushi Shibukawa, Atsushi Okamoto, Akihisa Tomita, Masanori Takabayashi, Kunihiro Sato
    JAPANESE JOURNAL OF APPLIED PHYSICS 50 9 09ME10.1-09ME10.5  2011年09月 [査読有り][通常論文]
     
    We proposed a new multilayer collinear holographic memory (MCHM) with a movable random phase mask that can act as an interlayer crosstalk reducer. First, to clarify the feasibility of our proposed device, we showed that it has an extremely sharp shift selectivity along the thickness direction of medium of nearly 5.0 mu m when the numerical aperture of the objective lens is 0.60. Next, we demonstrated that the utilization of the movable random phase mask can suppress interlayer crosstalk sufficiently, resulting in the improvement in the quality of reconstructed signals. Moreover, we revealed that the MCHM, in which the parallel use of a multilayered technique and collinear shift multiplexing is performed, brings out the medium potential sufficiently in terms of signal to noise ratio and medium dynamic range consumption. Finally, we verified that the MCHM can achieve a nearly 2 times larger data density at least compared with a conventional collinear holographic memory. (C) 2011 The Japan Society of Applied Physics
  • Atsushi Okamoto, Keisuke Kunori, Masanori Takabayashi, Akihisa Tomita, Kunihiro Sato
    OPTICS EXPRESS 19 14 13436 - 13444 2011年07月 [査読有り][通常論文]
     
    This study proposes holographic diversity interferometry (HDI), a system that combines information from spatially dispersed plural image sensors to reconstruct complex amplitude distributions of light signals. HDI can be used to generate four holographic interference fringes having different phases, thus enabling optical phase detection in a single measurement. Unlike conventional phase-shifting digital holography, this system does not require piezoelectric elements and phase shift arrays. In order to confirm the effectiveness of HDI, we generated optical signals having multilevel phases and amplitudes by using two SLMs and performed an experiment for detection and demodulation with HDI. (C) 2011 Optical Society of America
  • WAKAYAMA Yuta, OKAMOTO Atsushi, GRABAR Alexander A
    Ferroelectrics 415 207 - 214 2011年06月 [査読有り][通常論文]
  • Kaori Nishimaki, Atsushi Okamoto, Tomohiro Fujita, Alexander A. Grabar, Masanori Takabayashi, Jun Uozumi, Akihisa Tomita, Yoshihisa Takayama
    FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XXIII 7923 79230N  2011年 [査読無し][通常論文]
     
    Since the optical inter-satellite communication has attractive advantages such as high-speed transmission with high confidence, almost no electronic magnetic interference, and low power consumption, it has been activity investigated. However, directivity control of the laser beams requires a bulky and complicated system in satellite mobile communications. A more flexible and high accurate system with small and simple mechanism has been desired. In this study, we propose a new method of optical inter-satellite communication with a dynamically reconfigurable optical directional device in which diffraction gratings are automatically rewritten and reorganized in response of incident conditions by moving satellites. For realizing such a device, we have developed Sn2P2S6 crystals which have a high sensitive photorefractivity and dynamic reconfigurable property. Furthermore, this crystal has hundreds times faster response than conventional photorefractive materials such as BaTiO3. These features are extremely advantageous to construct a high-speed and flexible communication system with a large tolerance to displacement of moving satellites. To investigate the possibility of the dynamically reconfigurable optical inter-satellite communication system, we experimentally evaluate the temporal and spatial characteristics of Sn2P2S6 crystals for the variation of the beam incident angle. Moreover, the diffraction beam from the crystal has phase conjugate wavefronts of the beam entering from the counter direction. We try to utilize this behavior to suppress the beam spread and to reduce the background light such as sunlight with a spatial filtering technique that has sensitivity in wavefront differences of the signal and background light. (241words)
  • Takuya Oda, Atsushi Okamoto, Daiki Soma, Akihisa Tomita, Yuta Wakayama
    BROADBAND ACCESS COMMUNICATION TECHNOLOGIES V 7958 79580J  2011年 [査読無し][通常論文]
     
    We propose an all-optical demultiplexer based on dynamic multiple holograms using a photorefractive material for mode division multiplexing and optical MIMO processing systems. This demultiplexer can separate a specific spatial mode from multiplexed modes in a multi-mode fiber. In this study, we clarify a mode separation performance with various combinations of LP modes, and show the signal-to-noise ratio (SNR) can be improved by choosing appropriate mode combinations. In addition, to reveal the dependence of mode separation of the intensity ratio of the recording lights, we study the fluctuation of the SNR for LP0,1 mode by the combinations of multiplexed modes. Moreover, two additional recording techniques with a spatial light modulator (SLM) and phase conjugator are also proposed to improve the performance of the mode separation.
  • Yuta Wakayama, Atsushi Okamoto, Akihisa Tomita, Kunihiro Sato
    BROADBAND ACCESS COMMUNICATION TECHNOLOGIES V 7958 79580H  2011年 [査読無し][通常論文]
     
    We propose a reconfigurable optical add-drop multiplexer with ultra-broadband tuning range over 770 nm using a photorefractive polymer. This add-drop multiplexer can optically switch the assignment of the waveband used for communications by only changing the incident angles of two beams writing a hologram. In this work, we clarified the condition in which the channel tuning can be carried out without the location change in the port array. We simulated on the add-drop operation, and showed the ultra-wide tuning range from 780 to 1550 nm. Moreover, we suggested an apodization method for the grating distribution by controlling the intensity ratio of the writing beams to enhance the diffraction efficiency in add-drop operation. As a result, we showed that the apodization method for the grating distribution can improve the diffraction efficiency.
  • Autonomous and dynamic reconfigurable waveguide for optical interconnection with large shift-tolerance
    Proceedings of SPIE 7944 79440G  2011年 [査読無し][通常論文]
  • ODA Takuya, OKAMOTO Atsushi, SOMA Daiki, TOMITA Akihisa, WAKAYAMA Yuta
    Proc SPIE 7958 79580J.1-79580J.9  2011年 [査読無し][通常論文]
  • NISHIMAKI Kaori, OKAMOTO Atsushi, FUJITA Tomohiro, GRABAR Alexander A, TAKABAYASHI Masanori, UOZUMI Jun, TOMITA Akihisa, TAKAYAMA Yoshihisa
    Proc SPIE 7923 79230N.1-79230N.9  2011年 [査読無し][通常論文]
  • WAKAYAMA Yuta, OKAMOTO Atsushi, TOMITA Akihisa, SATO Kunihiro
    Proc SPIE 7958 79580H.1-79580H.8  2011年 [査読無し][通常論文]
  • 多層化コリニアホログラムによる超高密度記録
    岡本 淳, 渋川敦史
    光学 40 11 591 - 593 2011年 [査読無し][招待有り]
  • Yuta Wakayama, Atsushi Okamoto, Alexander A. Grabar, Kunihiro Sato
    Optical Review 18 1 117 - 123 2011年01月 [査読有り][通常論文]
     
    We propose a fundamental interconnection method using a polarization alignment system for waveguides having different spatial modes. In addition, as an example for the verification of the fundamental operation, we demonstrate an interconnection between a photonic crystal fiber and a laser that have obviously different spatial modes. The polarization alignment system operates synergistically with a self-written waveguide formed with a double phaseconjugate mirror. This technique enables us to interconnect a photonic crystal fiber with a laser source without complicated and time-consuming optical alignment. In this method, although it is not necessary to perform an external control for interconnection, the waveguide most suitable for connection is formed autonomously in a Sn2P2S6:Sb crystal developed for this purpose. There was a marked reduction in the polarization dependence of coupling efficiency, compared with that observed using a stand-alone double phase-conjugate mirror. © 2011 The Optical Society of Japan.
  • Masatoshi Bunsen, Seiji Fukuchi, Shuji Takahashi, Hirosuke Furuta, Atsushi Okamoto
    JAPANESE JOURNAL OF APPLIED PHYSICS 49 8 08KD06.1-08KD06.4  2010年08月 [査読有り][通常論文]
     
    A method for directional control of shift selectivities of speckle-multiplexed holograms with a diffuser whose diffusion angle varies with the diffusion direction is proposed to enhance the tolerance of recorded holograms to repositioning error in holographic storage. The directional dependence and controllability of shift selectivities of holograms are experimentally investigated using various diffusers. By retrieving 50 speckle-multiplexed holograms with deliberate deviations from the original recording position and by measuring bit error rate, it is also confirmed that the tolerance to repositioning error is improved. (C) 2010 The Japan Society of Applied Physics
  • WAKAYAMA Yuta, OKAMOTO Atsushi, GRABAR Alexander A
    Tech Dig Int Conf Opt photonics Des Fabr 7th 233 - 234 2010年 [査読有り][通常論文]
  • OKAMOTO Atsushi, MORITA Kazuyuki, WAKAYAMA Yuta, TANAKA Junya, SATO Kunihiro
    Proc SPIE 7716 771627.1-771627.10  2010年 [査読無し][通常論文]
  • Tanaka Junya, Okamoto Atsushi, Kitano Motoki
    Jpn J Appl Phys 48 3 03A028 - 03A028-5 INSTITUTE OF PURE AND APPLIED PHYSICS 2009年03月 [査読有り][通常論文]
     
    We apply the fast Fourier transform beam-propagation method (FFT-BPM) to analyze holographic data storage systems (HDSSs), and develop an image-based simulation for diffraction characteristics in a transmission-type HDSS. The FFT-BPM is known as a very effective method for the design of large waveguides. By applying this method, we can obtain a beam profile in a recording medium that consists of a three-dimensional (3D) complex refractive-index distribution, and analyze the diffraction characteristics in page-oriented multiplexing holograms for an analytic region more practical than that required for the finite-difference time-domain (FDTD) method because of much lower computation time and memory. In this study, we demonstrate angular multiplexing by recording three data pages at different angles and visualize angular selectivity for diffraction efficiency and the sharpness of reconstructed images by a 3D numerical simulation.
  • Takabayashi Masanori, Okamoto Atsushi, Sato Kunihiro
    Jpn J Appl Phys 48 3 03A032 - 03A032-5 INSTITUTE OF PURE AND APPLIED PHYSICS 2009年03月 [査読有り][通常論文]
     
    Holographic data storage with phase-modulated signals has great advantages over conventional intensity-based memory. These include the efficient use of material dynamic range and light power in a spatial light modulator. On the other hand, phase-based holographic data storage has a disadvantage, which is the difficulty in distinguishing phase-modulated signals. We propose and demonstrate a new phase-modulated signal detection method with photorefractive two-wave mixing. This method has several advantages such as high energy efficiency, detection of multi valued phase-modulated signals, and alignment-free optics. In this study, we investigate the spatial resolution of the phase-modulated signal detection method and obtain a spatial resolution of 300–500 μm of incident pixels.
  • Kitano Motoki, Okamoto Atsushi, Sano Takayuki
    Jpn J Appl Phys 48 3 03A036 - 03A036-6 INSTITUTE OF PURE AND APPLIED PHYSICS 2009年03月 [査読有り][通常論文]
     
    To determine the degree of security in two-wave encryption under practical conditions, we present a novel numerical technique for simulating the recording and readout of two-wave encryption. The calculation results of the retrieval characteristics show that the diffraction efficiency in an incorrect decryption is 10 times as low as that in correct decryption key and that the output data with an incorrect key is a white noise image. We estimate the necessary key correlation to decrypt an encrypted data is 0.2 when the length of an encryption key is 2313. This means that the decoding probability of the encryption key in two-wave encryption is less than $10^{-6}$ even if such a short key is used.
  • Yasunori Kojima, Atsushi Okamoto, Alexander A. Grabar, Masanori Takabayashi, Kohei Shimayabu
    FERROELECTRICS 378 121 - 128 2009年 [査読有り][通常論文]
     
    We present various optical basic properties of a 1.5% doped Sb:Sn2P2S6 crystal experimentally and demonstrate a double phase conjugate mirror (DPCM). We measured the reflection, absorption and scattering of this crystal. The large coupling strength L = 8.2 was obtained by the experiment of two-wave mixing. In addition, we succeeded in the formation of the DPCM and achieved the high diffraction efficiency of 42%. This crystal was suitable for DPCM applications of high speed response.
  • Atsushi Okamoto, Kazuhiro Harasaka, Masatoshi Bunsen, Masanori Takabayashi, Shuji Rokutanda
    JOURNAL OF MODERN OPTICS 56 12 1323 - 1334 2009年 [査読有り][通常論文]
     
    Spatial resolutions of diffracted beams by photorefractive polymers are investigated in detail for applying the polymers to diffractive optical elements. The coupled wave equations for the four-wave mixing in photorefractive polymers and their solutions by applying the two-beam coupling approximation are derived taking the orientational enhancement effect into consideration. Characteristics of the diffraction efficiency of the polymers for the applied electric field, the incident angles of beams, the incident radiation intensity and the polarization are clarified. Furthermore, resolutions of diffracted images with the polymers are discussed by a numerical analysis from the viewpoint of the Bragg diffraction in a spatial frequency domain. An experiment with the TPD (tetra-phenyl-diphenyldiamine) acrylate based photorefractive polymers and the USAF test target is also performed to measure the spatial resolution of two-dimensional images diffracted by the polymer and to verify the calculated results. It is revealed that high resolution over 50 lp mm-1 can be obtained with sufficient diffraction efficiency in the case of the polymer thickness of several 10 mu m.
  • Ito T, Okamoto A, Sato K
    Applied optics 46 23 5902 - 5911 2007年08月 [査読有り][通常論文]
  • Digital image multiplexing/demultiplexing method using spatial spectral diffusion and virtual phase conjugation technique for reduction of dynamic range consumption in holographic medium
    Yuta Goto, Atsushi Okamoto, Masanori Takabayashi, Kazuhisa Ogawa, Akihisa Tomita
    Japanese Journal of Applied Physics 56 98 09NA07-1 - 09NA07-8 2007年08月 [査読有り][通常論文]
  • Ito T, Okamoto A, Funakoshi H, Sato K
    Applied optics 46 13 2443 - 2452 2007年05月 [査読有り][通常論文]
  • Bunsen M, Furuta H, Okamoto A
    Applied optics 45 27 7035 - 7042 2006年09月 [査読有り][通常論文]
  • Bunsen M, Okamoto A
    Applied optics 44 8 1454 - 1463 2005年03月 [査読有り][通常論文]

書籍

  • ホログラム最新技術~感光材料の開発から実製品への応用まで~
    情報機構 2007年
  • ホログラフィックメモリーのシステムと材料
    シーエムシー出版 2006年
  • Systems, Devices and Materials for the Holographic Data Storage
    2006年

講演・口頭発表等

その他活動・業績

  • 鈴木 貴士, 富田 章久, 岡本 淳 電子情報通信学会総合大会講演論文集 2012 2012年03月06日 [査読無し][通常論文]
  • Nishimaki Kaori, Okamoto Atsushi, Wakayama Yuta, Tomita Akihisa, Takayama Yoshihisa 電子情報通信学会技術研究報告. SAT, 衛星通信 111 (336) 137 -140 2011年12月05日 [査読無し][通常論文]
     
    We propose an innovative acquisition and tracking system using a dynamically reconfigurable optical device for optical inter-satellite communication without growing in size and complications due to directivity control of laser beams. The proposed system provides relaxation of acquisition accuracy and suppression of beam divergence by utilization of phase conjugation to form an inter-satellite communication link. This paper reports on the temporal and spatial characteristics of our system for various incident beam angles to consider relaxation of acquisition accuracy and tracking speed.
  • 青木 洸平, 岡本 淳, 富田 章久, 本間 聡 電子情報通信学会ソサイエティ大会講演論文集 2011 (2) 2011年08月30日 [査読無し][通常論文]
  • 相馬 大樹, 岡本 淳, 小田 拓哉, 富田 章久, 佐藤 邦宏 電子情報通信学会ソサイエティ大会講演論文集 2011 (2) 2011年08月30日 [査読無し][通常論文]
  • 小田 拓哉, 岡本 淳, 相馬 大樹, 富田 章久 電子情報通信学会技術研究報告. LQE, レーザ・量子エレクトロニクス 111 (186) 75 -80 2011年08月18日 [査読無し][通常論文]
     
    本研究は,マルチモードファイバを用いたモード分割多重(MDM)通信を,動的多重ホログラムで構成された全光学的デマルチプレクサにより実現することを目的としている.本稿では3多重のMDM信号の分離を想定し,3つの異なるLPモードで構成される組み合わせを6通り用意し,デマルチプレクサのモード分離特性を調査した.また,分離特性の向上のため,ホログラム記録時に用いられる2本の光の強度比を変化させ,モード分離の強反比依存性を明らかにした.さらに,LPモードの組み合わせと強度比を適切に選択することで,高いSNRが得られることを示した.
  • Strongly confined light in a singe mode near quantum dots embedded in photonic crystals
    Proceedings of NUSOD 2011 TuD6 2011年 [査読無し][通常論文]
  • Apodization along thickness direction of holographic transmission grating in Sb-doped Sn2P2S6
    Proceedings of NUSOD 2011 M11 2011年 [査読無し][通常論文]
  • Double‐Referential Collinear Holographic Memory and Spatial Quadrature Amplitude Modulation
    Technical Digest of The Joint International Symposium on Optical Memory and Optical Data Storage 2011 (ISOM/ODS’11) OTuD12 2011年 [査読無し][通常論文]
  • Holographic Diversity Detection of Spatial Quadrature Amplitude Modulation Signal for Dual‐Stage Holographic Memory
    Technical Digest of The Joint International Symposium on Optical Memory and Optical Data Storage 2011 (ISOM/ODS’11) OMB3 2011年 [査読無し][通常論文]
  • Evaluation of the Performance in Multilayer Collinear Holographic Memory with Movable Random Phase Mask
    Technical Digest of The Joint International Symposium on Optical Memory and Optical Data Storage 2011 (ISOM/ODS’11) OMD16 2011年 [査読無し][通常論文]
  • Self‐Referential Holographic Data Storage by Phase‐Modulation Technique
    Technical Digest of The Joint International Symposium on Optical Memory and Optical Data Storage 2011 (ISOM/ODS’11) OMB4 2011年 [査読無し][通常論文]
  • High‐Speed Full Motion Analysis Based on FFT-BPM for Collinear Holographic Memory
    Technical Digest of The Joint International Symposium on Optical Memory and Optical Data Storage 2011 (ISOM/ODS’11) OMD22 2011年 [査読無し][通常論文]
  • OKAMOTO Atsushi, ODA Takuya, MORITA Kazuyuki Tech Dig Int Conf Opt photonics Des Fabr 7th 169 -170 2010年 [査読有り][通常論文]
  • Spatial Arrangement of Speckle-Multiplexed Holograms Using Directional Control of Shift Selectivity with Holographic Diffuser
    IEEE TENCON2010 T10-2.P1 2010年 [査読無し][通常論文]
  • Spatial Quadrature Amplitude Modulation Method by Dual-Stage Holographic Memory
    Technical Digest of IWHM&D 2010 49 2010年 [査読無し][通常論文]
  • Dual-Stage Holographic Memory based on Optical Recording and Digital Readout Technique
    Technical Digest of MOC 2010(CD-ROM) WP62 2010年 [査読無し][通常論文]
  • Experiment on Separating of LP Modes by Dynamic Multiplex Holographic Element for Mode Division Multiplex Communication
    Technical Digest of MOC 2010(CD-ROM) WB2 2010年 [査読無し][通常論文]
  • High Performance Intersatellite Communication Based on Background Light Reduction Technique with Double Phase Conjugate Mirror
    Technical Digest of MOC 2010(CD-ROM) WP44 2010年 [査読無し][通常論文]
  • Experiment on Photorefractive Collinear Holographic Data Storage by Semicircular Phase-Shift Methods
    Technical Digest of IWHM&D 2010 53 2010年 [査読無し][通常論文]
  • Low Inter-page Crosstalk Recording by Multi-layer Collinear Holographic Memory
    Technical Digest of ISOM 2010(CD-ROM) Th-N-03 2010年 [査読無し][通常論文]
  • Symbol Error Rate Characteristics of Hybrid-Modulated Holographic Data Storage with Multi-Phase and 2/4 Intensity Modulation Code
    Technical Digest of ISOM 2010(CD-ROM) Th-N-02 2010年 [査読無し][通常論文]
  • Demonstration of Optical Threshold Secret Sharing Scheme with Secure Holographic Memory and Mutually Pumped Phase Conjugator
    Technical Digest of ISOM 2010(CD-ROM) Mo-E-03 2010年 [査読無し][通常論文]
  • Full Motion Analysis for Holographic Memory by Three-Dimensional Fast Fourier Transform Beam-Propagation Method
    Technical Digest of ISOM 2010(CD-ROM) Tu-I-14 2010年 [査読無し][通常論文]
  • Low-loss Coherent of Light Confined Near a Defect in Photonic Crystal
    Technical Digest of ISOM 2010(CD-ROM) Mo-B-04 2010年 [査読無し][通常論文]
  • Targeted optical control of confined light inside photonic crystals
    The proceedings of the Fourth International Congress on Advanced Electromagnetic Materials in Microwaves and Optics (Metamaterials 2010) 16 2010年 [査読無し][通常論文]
  • Photorefractive Collinear Holographic Data Storage by Phase Shift Recording
    Fourth International Conference on Optical, Optelectronic and Photonic Materials and Applications (ICOOPMA 2010) A-0082 2010年 [査読無し][通常論文]
  • All-Optical Reconfigurable Add-Drop Multiplexer with Photorefractive Sn2P2S6:Sb Crystal
    Fourth International Conference on Optical, Optelectronic and Photonic Materials and Applications (ICOOPMA 2010) A-0080 2010年 [査読無し][通常論文]
  • Experiment on Dynamic Reconfigurable Diffraction Element for Mode Division Multiplex Communication
    Technical Digest of the 15th Optoelectronics and Communications Conference (OECC 2010) 7P-23 2010年 [査読無し][通常論文]
  • Improvement of Diffraction Efficiency for All-Optical Tunable Wavelength Filter by Apodized Photorefractive Grating
    Technical Digest of the 15th Optoelectronics and Communications Conference (OECC 2010) 8P-65 2010年 [査読無し][通常論文]
  • Compatibility to WDM of Volume Holographic Demultiplexer for Spatial Mode Division Multiplexing
    Technical Digest of the 15th Optoelectronics and Communications Conference (OECC 2010) 7E4-3 2010年 [査読無し][通常論文]
  • Polarization Dependence of Double Phase Conjugate Mirror with Sn2P2S6:Sb 1.5% Crystals
    Abstract Book of the 10th Russia/CIS/Baltic/Japan Symposium on Ferroelectricity (RCBJSF-10) 193 2010年 [査読無し][通常論文]
  • Mode division multiplex communication technique based on dynamic volume hologram and phase conjugation
    Proceedings of SPIE (Photonics Europe 2010) 7716-78 771627 2010年 [査読無し][通常論文]
  • All-optical Demultiplexer for mode division multiplex communication technique with a multimode optical fiber
    Technical Digest of 7th International Conference on Optics-photonics Design & Fabrication (ODF’10) 20PSa-57 2010年 [査読無し][通常論文]
  • Polarization Alignment Free Interconnection by Dynamically Reconfigurable Double Phase Conjugation
    Technical Digest of 7th International Conference on Optics-photonics Design & Fabrication (ODF’10) 20S3-05 2010年 [査読無し][通常論文]
  • 若山 雄太, 岡本 淳, グラバール アレクサンダー A 電子情報通信学会ソサイエティ大会講演論文集 2009 (1) 2009年09月01日 [査読無し][通常論文]
  • Junya Tanaka, Atsushi Okamoto, Motoki Kitano JAPANESE JOURNAL OF APPLIED PHYSICS 48 (3) 03A028 2009年03月 [査読無し][通常論文]
     
    We apply the fast Fourier transform beam-propagation method (FFT-BPM) to analyze holographic data storage systems (HDSSs), and develop an image-based simulation for diffraction characteristics in a transmission-type HDSS. The FFT-BPM is known as a very effective method for the design of large waveguides. By applying this method, we can obtain a beam profile in a recording medium that consists of a three-dimensional (3D) complex refractive-index distribution, and analyze the diffraction characteristics in page-oriented multiplexing holograms for an analytic region more practical than that required for the finite-difference time-domain (FDTD) method because of much lower computation time and memory. In this study, we demonstrate angular multiplexing by recording three data pages at different angles and visualize angular selectivity for diffraction efficiency and the sharpness of reconstructed images by a 3D numerical simulation. 2009 The Japan Society of Applied Physics DOI: 10.1143/JJAP.48.03A028
  • Masanori Takabayashi, Atsushi Okamoto, Kunihiro Sato JAPANESE JOURNAL OF APPLIED PHYSICS 48 (3) 03A032 2009年03月 [査読無し][通常論文]
     
    Holographic data storage with phase-modulated signals has great advantages over conventional intensity-based memory. These include the efficient use of material dynamic range and light power in a spatial light modulator. On the other hand, phase-based holographic data storage has a disadvantage, which is the difficulty in distinguishing phase-modulated signals. We propose and demonstrate a new phase-modulated signal detection method with photorefractive two-wave mixing. This method has several advantages such as high energy efficiency, detection of multi valued phase-modulated signals, and alignment-free optics. In this study, we investigate the spatial resolution of the phase-modulated signal detection method and obtain a spatial resolution of 300-500 mu m of incident pixels. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/JJAP.48.03A032
  • Motoki Kitano, Atsushi Okamoto, Takayuki Sano JAPANESE JOURNAL OF APPLIED PHYSICS 48 (3) 03A036 2009年03月 [査読無し][通常論文]
     
    To determine the degree of security in two-wave encryption under practical conditions, we present a novel numerical technique for simulating the recording and readout of two-wave encryption. The calculation results of the retrieval characteristics show that the diffraction efficiency in an incorrect decryption is 10 times as low as that in correct decryption key and that the output data with an incorrect key is a white noise image. We estimate the necessary key correlation to decrypt an encrypted data is 0.2 when the length of an encryption key is 2313. This means that the decoding probability of the encryption key in two-wave encryption is less than 10(-6) even if such a short key is used. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/JJAP.48.03A036
  • Fumiaki Matsuoka, Hiroyuki Nihei, Atsushi Okamoto PHOTONIC AND PHONONIC CRYSTAL MATERIALS AND DEVICES IX 7223 72231F.1-72231F.8 2009年 [査読無し][通常論文]
     
    We demonstrate that the emission spectrum from a quantum dot near the edge of a photonic band gap (PBG) can be spectrally resolved on the subwavelength scale using coherent control. In the case of the coherent control, confined light near a quantum dot embedded in photonic crystals can be released by changing the phase of the external laser phase, without closing the PBG. Moreover, in this demonstration, we examine the spectrum resolution of the coherent control, which indicates that the spectrum resolution is the subwavelength scale. Therefore, even if there are many quantum dots are embedded in photonic crystals, we can be operated a quantum dot with a specific resonant frequency. This technique may provide a basis for N-qubit operation for quantum computations and nanophotonic devices.
  • Masanori Takabayashi, Atsushi Okamoto ADVANCED OPTICAL CONCEPTS IN QUANTUM COMPUTING, MEMORY, AND COMMUNICATION II 7225 72250G.1-72250G.8 2009年 [査読無し][通常論文]
     
    We develop a photorefractive time-domain differential detection (PR-TDDD) method in holographic data storage systems with considering the temporal response of photorefractive two-wave mixing (PR-TWM). Optimizing the parameters of PR-TDDD method provides high-precision distinction of phase-modulated signals, i.e. distinction of small phase difference. In PR-TDDD method, the phase information can be sequentially-distinguished by monitoring the output intensity of PR-TWM. This is because the output intensity of PR-TWM is changed when the signal phase is changed. In addition, the changing rate of the output intensity corresponds to that of the signal phase. The advantages of our method are high energy efficiency, alignment-free optics and the distinction of multi-valued phase-modulated signals. Especially, we focus attention on applying to phase-based holographic data storage systems, which can achieve homogeneous intensity distribution on recording plane, i.e. Fourier transform plane, in general, and high energy efficiency because of 100% white rate. More noteworthy is that multi-valued phase-based holographic data storage can be realized by using PR-TDDD method. In this work, we consider the important parameters in PR-TDDD method; signal-to-pump beam intensity ratio, photorefractive coupling strength, and photorefractive time constant. The balance between these parameters is important for realizing the high-precision distinction of phase-modulated signal.
  • Shift selectivity in multi-layered collinear holographic system by medium shift along the thickness direction
    Technical Digest of IWHM&D 2009 13 -14 2009年 [査読無し][通常論文]
  • Fundamental Experiment on Rewritable Collinear Holographic Data Storage
    Technical Digest of IWHM&D 2009 35 -36 2009年 [査読無し][通常論文]
  • Dynamically reconfigurable optical device with nanoscale dynamic self-organization in Sn2P2S6 crystal
    Technical Digest of the 7th Asia-Pacific Conference on Near-Field Optics (APNFO-7) 127 2009年 [査読無し][通常論文]
  • Spectrum resolution of a coherent control of Er3+ ions embedded in inverse opal structure
    Technical Digest of the 7th Asia-Pacific Conference on Near-Field Optics (APNFO-7) 128 2009年 [査読無し][通常論文]
  • Apodization method by nonuniform spatial distribution of diffraction gratings for photorefractive wavelength filter
    Asia Communications and Photonics Conference and Exhibition (ACP 2009) WL15 2009年 [査読無し][通常論文]
  • Volume Holographic Demultiplexer for Spatial Mode Division Multiplexing in Optical Fiber Communication
    Asia Communications and Photonics Conference and Exhibition (ACP 2009) WL16 2009年 [査読無し][通常論文]
  • Spatial Filtering System on Optical Intersatellite Communication with Double Phase Conjugate Mirror
    Asia Communications and Photonics Conference and Exhibition (ACP 2009) WL54 2009年 [査読無し][通常論文]
  • Coherent Control of Targeted Quantum Dot in Photonic Crystals for Nanophotonics Devices
    Asia Communications and Photonics Conference and Exhibition (ACP2009) FQ2 2009年 [査読無し][通常論文]
  • Dynamically reconfigurable fiber coupling by polarization-independent double phase-conjugation
    Technical Digest of MOC 2009 272 -273 2009年 [査読無し][通常論文]
  • Directional control of shift selectivity of speckle-multiplexed holograms for improving repositioning tolerance
    Technical Digest of ISOM 2009 Tu-G-18 2009年 [査読無し][通常論文]
  • Reproducing evaluations of optical threshold secret sharing technique based on two-wave encryption
    Technical Digest of ISOM 2009 Tu-G-33 2009年 [査読無し][通常論文]
  • Phase-oriented simulation for shift-multiplexed holographic data storage system by fast-Fourier transform beam-propagation method
    Technical Digest of ISOM 2009 Tu-G-26 2009年 [査読無し][通常論文]
  • Phase-differential modulation for phase-based holographic data storage with photorefractive time-domain differential detection method
    Technical Digest of ISOM 2009 Tu-G-32 2009年 [査読無し][通常論文]
  • High Speed Phase Detection for Holographic Data Storage by Photorefractive Time-Domain Differential Detection with Sb: Sn2P2S6 Crystal
    Photonics in Switching 2009 (PS2009) ThI3-5 2009年 [査読無し][通常論文]
  • Optical interconnection for multi-wavelength signals with volume holographic router
    Technical Digest of 12th Optoelectronics and Communications Conference (OECC 2009) ThLP 73 2009年 [査読無し][通常論文]
  • Targeted coherent control inside photonic band gaps for nanophotonics devices
    Technical Digest of 12th Optoelectronics and Communications Conference (OECC 2009) Tul 2 2009年 [査読無し][通常論文]
  • Dynamically Reconfigurable Optical Waveguides with Sn2P2S6 Crystal for Free Space Optical Wiring
    Technical Digest of 14th Optoelectronics and Communications Conference (OECC 2009) ThLP 13 2009年 [査読無し][通常論文]
  • Atsushi Okamoto, Kazuhiro Harasaka, Masatoshi Bunsen, Masanori Takabayashi, Shuji Rokutanda JOURNAL OF MODERN OPTICS 56 (12) 1323 -1334 2009年 [査読無し][通常論文]
     
    Spatial resolutions of diffracted beams by photorefractive polymers are investigated in detail for applying the polymers to diffractive optical elements. The coupled wave equations for the four-wave mixing in photorefractive polymers and their solutions by applying the two-beam coupling approximation are derived taking the orientational enhancement effect into consideration. Characteristics of the diffraction efficiency of the polymers for the applied electric field, the incident angles of beams, the incident radiation intensity and the polarization are clarified. Furthermore, resolutions of diffracted images with the polymers are discussed by a numerical analysis from the viewpoint of the Bragg diffraction in a spatial frequency domain. An experiment with the TPD (tetra-phenyl-diphenyldiamine) acrylate based photorefractive polymers and the USAF test target is also performed to measure the spatial resolution of two-dimensional images diffracted by the polymer and to verify the calculated results. It is revealed that high resolution over 50 lp mm-1 can be obtained with sufficient diffraction efficiency in the case of the polymer thickness of several 10 mu m.
  • Link Budget Analysis for Optical Intersatellite Communication System with Double Phase Conjugate Mirror
    Proceedings of 1st International Conference on Space Optical Systems and Applications (ICSOS) 32 2009年 [査読無し][通常論文]
  • Proceedings of SPIE (Photonics West 2009, San Jose, USA) 7223 72231F1-72231F8 2009年 [査読無し][通常論文]
  • Photorefractive splicing device with double phase conjugate mirror using Sn2P2S6:Sb crystals
    Proceedings of SPIE (Photonics West 2009, San Jose, USA) 7212 72120Q1-72120Q10 2009年 [査読無し][通常論文]
  • Masanori Takabayashi, Atsushi Okamoto ADVANCED OPTICAL CONCEPTS IN QUANTUM COMPUTING, MEMORY, AND COMMUNICATION II 7225 72250G1-72250G8 2009年 [査読無し][通常論文]
     
    We develop a photorefractive time-domain differential detection (PR-TDDD) method in holographic data storage systems with considering the temporal response of photorefractive two-wave mixing (PR-TWM). Optimizing the parameters of PR-TDDD method provides high-precision distinction of phase-modulated signals, i.e. distinction of small phase difference. In PR-TDDD method, the phase information can be sequentially-distinguished by monitoring the output intensity of PR-TWM. This is because the output intensity of PR-TWM is changed when the signal phase is changed. In addition, the changing rate of the output intensity corresponds to that of the signal phase. The advantages of our method are high energy efficiency, alignment-free optics and the distinction of multi-valued phase-modulated signals. Especially, we focus attention on applying to phase-based holographic data storage systems, which can achieve homogeneous intensity distribution on recording plane, i.e. Fourier transform plane, in general, and high energy efficiency because of 100% white rate. More noteworthy is that multi-valued phase-based holographic data storage can be realized by using PR-TDDD method. In this work, we consider the important parameters in PR-TDDD method; signal-to-pump beam intensity ratio, photorefractive coupling strength, and photorefractive time constant. The balance between these parameters is important for realizing the high-precision distinction of phase-modulated signal.
  • High sensitive and efficient photorefractive tunable optical wavelength filter with applied external field
    Proceedings of SPIE (Photonics West 2009, San Jose, USA) 7212 72120W1-72120W9 2009年 [査読無し][通常論文]
  • Yasunori Kojima, Atsushi Okamoto, Alexander A. Grabar, Masanori Takabayashi, Kohei Shimayabu FERROELECTRICS 378 121 -128 2009年 [査読無し][通常論文]
     
    We present various optical basic properties of a 1.5% doped Sb:Sn2P2S6 crystal experimentally and demonstrate a double phase conjugate mirror (DPCM). We measured the reflection, absorption and scattering of this crystal. The large coupling strength L = 8.2 was obtained by the experiment of two-wave mixing. In addition, we succeeded in the formation of the DPCM and achieved the high diffraction efficiency of 42%. This crystal was suitable for DPCM applications of high speed response.
  • Journal of Modern Optics 55 (15) 2391 -2399 2008年09月10日 [査読無し][通常論文]
  • Nihei Hiroyuki, Okamoto Atsushi Jpn J Appl Phys 47 (7) 5781 -5783 2008年07月25日 [査読無し][通常論文]
     
    We demonstrate optical control of an active medium, such as a quantum dot or an impurity atom, embedded in three-dimensional photonic crystals. The optical control provides a very high spectral selectivity, which allows us to control confined light near a targeted active medium with a specific resonant frequency. Using such an optical control, even if the other active mediums are embedded nearby, we may selectively control only the targeted active medium, leading to a basic operation of an optical memory on the nanoscale below the light wavelength.
  • Hiroyuki Nihei, Atsushi Okamoto Japanese Journal of Applied Physics 47 (7) 5781 -5783 2008年07月18日 [査読無し][通常論文]
     
    We demonstrate optical control of an active medium, such as a quantum dot or an impurity atom, embedded in three-dimensional photonic crystals. The optical control provides a very high spectral selectivity, which allows us to control confined light near a targeted active medium with a specific resonant frequency. Using such an optical control, even if the other active mediums are embedded nearby, we may selectively control only the targeted active medium, leading to a basic operation of an optical memory on the nanoscale below the light wavelength.
  • Masatoshi Bunsen, Hirosuke Furuta, Kuniaki Aragane, Atsushi Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS 47 (7) 5977 -5980 2008年07月 [査読無し][通常論文]
     
    Novel holographic recording configurations capable of selective erasure of multiplexed holograms for data-page rewriting in holographic storage are presented. By using a half wave plate and a polarizing beam splitter as the phase control device of the interference pattern in holographic recording/erasure procedure, comparatively large-area and finespun data-pages may be recorded, selectively erased, and rewritten in simple operations. We experimentally demonstrate the selective erasure of multiplexed data-pages in photorefractive iron-doped LiNbO(3) crystals, and show the effectiveness of the configuration. We also propose a method to improve the in-plane uniformity of the erasure making use of the diffuser in the optical path of the object beam which is employed for dispersing the object image and the phase conjugate readout technique.
  • Masatoshi Bunsen, Hirosuke Furuta, Kuniaki Aragane, Atsushi Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS 47 (7) 5977 -5980 2008年07月 [査読無し][通常論文]
     
    Novel holographic recording configurations capable of selective erasure of multiplexed holograms for data-page rewriting in holographic storage are presented. By using a half wave plate and a polarizing beam splitter as the phase control device of the interference pattern in holographic recording/erasure procedure, comparatively large-area and finespun data-pages may be recorded, selectively erased, and rewritten in simple operations. We experimentally demonstrate the selective erasure of multiplexed data-pages in photorefractive iron-doped LiNbO(3) crystals, and show the effectiveness of the configuration. We also propose a method to improve the in-plane uniformity of the erasure making use of the diffuser in the optical path of the object beam which is employed for dispersing the object image and the phase conjugate readout technique.
  • Hiroyuki Nihei, Atsushi Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS 47 (7) 5781 -5783 2008年07月 [査読無し][通常論文]
     
    We demonstrate optical control of an active medium, such as a quantum dot or an impurity atom, embedded in three-dimensional photonic crystals. The optical control provides a very high spectral selectivity, which allows us to control confined light near a targeted active medium with a specific resonant frequency. Using such an optical control, even if the other active mediums are embedded nearby, we may selectively control only the targeted active medium, leading to a basic operation of an optical memory on the nanoscale below the light wavelength.
  • Atsushi Okamoto, Kazuhiro Harasaka, Hidenobu Muranaka, Takayuki Sano, Akinori Nishio JOURNAL OF MODERN OPTICS 55 (2) 311 -322 2008年 [査読無し][通常論文]
     
    We propose an image cross-connector using an organic photorefractive polymer. With this device, it is possible to perform a reconfigurable connection between multiple input-output image ports by setting the incident angle of individual control beams to minute levels. The use of a polymer can reduce the thickness of the index grating to be induced inside the medium, which can also reduce the distortion of the output image and bring about high precise image connection without an additional optical system. We conduct an experiment with a hole-transport polymer PATPD to verify the operations of an image cross-connector, in which different images from a vertical array of input images would be connected separately to two output ports by two control beams that were injected at different angles.
  • High-resolution coherent control of a quantum dot embedded in photonic crystals
    Proceedings of IEEE, Photonics Global 2008 PA-14 2008年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto JOURNAL OF MODERN OPTICS 55 (15) 2391 -2399 2008年 [査読無し][通常論文]
     
    We demonstrate the coherent control of the excited state of an atom embedded in three-dimensional photonic bandgap (3D PBG) structures. The coherent control allows us to obtain a long-lifetime Rabi oscillation or several types of steady-state inversion, depending on the laser phase, in which the relaxation of an excited atom is strongly suppressed. Such a coherent control suggests the possibility of extending the atomic system to a low loss quantum logic gate for optical quantum computation.
  • Optical Intersatellite Communication System with Double Phase Conjugate Mirror
    34th European Conference and Exhibition on Optical communication 2008 P.4.05 2008年 [査読無し][通常論文]
  • Analysis of double phase-conjugate mirror using the FD-BPM
    International Conference on Photonics in Switching 2008 P-3 2008年 [査読無し][通常論文]
  • Nano-photonic switching in a quantum dot embedded in photonic crystals
    International Conference on Photonics in Switching 2008 P-15 2008年 [査読無し][通常論文]
  • Suppression of crosstalk by apodization of photorefractive transmission grating for wavelength filter
    International Conference on Photonics in Switching 2008 P-12 2008年 [査読無し][通常論文]
  • Simulation technique for diffraction efficiency characteristics in holographic data storage system based on FFT-BPM
    Technical Digest of ISOM/ODS 2008 87 -89 2008年 [査読無し][通常論文]
  • Numerical Simulation of Retrieving Characteristics in Holographic Data Storage by Two-Wave Encryption
    Technical Digest of ISOM/ODS 2008 90 -92 2008年 [査読無し][通常論文]
  • Spatial Resolution of Phase-Modulated Signal Detection Method using Photorefractive Two-Wave Mixing for Holographic Data Storage System
    Technical Digest of ISOM/ODS 2008 81 -83 2008年 [査読無し][通常論文]
  • Selective Erasure of Multiplexed Holograms Using Beam Amplification by Mutually Pumped Phase Conjugate Mirror
    Technical Digest of ISOM/ODS 2008 78 -80 2008年 [査読無し][通常論文]
  • Nanophotonic Active Devices using Tunability of Photonic Band Gap
    ABSTRACT BOOK of Russia/CIS/Baltic/Japan symposium on Ferroelectricity (RCBJSF-9) 64 -64 2008年 [査読無し][通常論文]
  • Double Phase Conjugate Mirror in a Photorefractive Sb:Sn2P2S6 Crystal
    ABSTRACT BOOK of Russia/CIS/Baltic/Japan symposium on Ferroelectricity (RCBJSF-9) 165 -165 2008年 [査読無し][通常論文]
  • Atsushi Okamoto, Kazuhiro Harasaka, Hidenobu Muranaka, Takayuki Sano, Akinori Nishio JOURNAL OF MODERN OPTICS 55 (2) 311 -322 2008年 [査読無し][通常論文]
     
    We propose an image cross-connector using an organic photorefractive polymer. With this device, it is possible to perform a reconfigurable connection between multiple input-output image ports by setting the incident angle of individual control beams to minute levels. The use of a polymer can reduce the thickness of the index grating to be induced inside the medium, which can also reduce the distortion of the output image and bring about high precise image connection without an additional optical system. We conduct an experiment with a hole-transport polymer PATPD to verify the operations of an image cross-connector, in which different images from a vertical array of input images would be connected separately to two output ports by two control beams that were injected at different angles.
  • Satoshi Honma, Shinzo Muto, Atsushi Okamoto HOLOGRAPHY AND DIFFRACTIVE OPTICS III 6832 68322P 2008年 [査読無し][通常論文]
     
    Holographic technologies for optical memories and interconnection devices have been studied actively because of high Storage capacity.. many wiring patterns and high transmission rate. Among multiplexing techniques such as angular, phase code and wavelength-multiplexing, speckle multiplexing technique have gotten attention due to the simple optical setup having an adjustable random phase filter in only one direction. To keep simple construction and to suppress crosstalk among adjacent page data or wiring patterns for efficient ZD holographic memories and interconnection, we have to consider about optimum randomness of the phase filter. The high randomness causes expanding an illumination area of reference beam on holographic media. On the other hands, the small randomness causes the crosstalk between adjacent hologram data. We have proposed the method of holographic multiplexing, shift-phase code multiplexing with a two-dimensional orthogonal matrix phase filter. A lot of orthogonal phase codes can be produced by shifting the phase filter in one direction. It is able to read and record the individual holograms with low crosstalk. We give the basic experimental result on holographic data multiplexing and consider the phase pattern of the filter to suppress the crosstalk between adjacent holograms sufficiently.
  • 吉田 拓史, 岡本 淳, 本間 聡 電子情報通信学会技術研究報告. EMD, 機構デバイス 107 (196) 139 -143 2007年08月16日 [査読無し][通常論文]
     
    フォトリフラクティブ(PR)結晶を用いた波長フィルタにおいて,PR結晶内の透過型屈折率格子のアポダイゼーションによるクロストークの抑制手法を提案する.PR結晶中にコヒーレントな2光波を照射すると,PR効果によって屈折率格子が誘起され,書き込み光間に非対称なエネルギー移動が生じる.このPR結晶内の屈折率格子をアポダイゼーションすることでクロストークの抑制が可能である.本稿では,書き込み光強度比に対する出力光の帯域幅を解析し,クロストークを抑制するのに最適な書き込み光強度比を明らかにする.γL-6.0の条件で,アポタイゼーションしない場合と比較して,約4dBのクロストークの抑制が見られた.
  • 高橋 伸弘, 岡本 淳, 佐野 貴之, 伊藤 輝将 電子情報通信学会技術研究報告. EMD, 機構デバイス 107 (196) 133 -137 2007年08月16日 [査読無し][通常論文]
     
    ホログラフィックROMを短時間で複製することを目的として,フォトリフラクティブ増幅器(PRA)を用いた高速複製システムを提案する.マスターホログラム媒体から再生された極めて弱い回折光を,PRAを用いて増幅することにより,短時間でのホログラフィックROMの複製が可能となる.本システムが,どの程度ホログラフィックROMを高速に複製できるかを,PRAを用いずに複製する場合と比較することにより示す.本システムには,PRAにより得られる利得がビームの入射角度に依存することから,コピーホログラムの回折効率が不均一になるという問題点がある.そこで本稿では,マスターホログラムの回折効率を記録スポットごとに調節することにより,コピーホログラムの回折効率を均一化できることを示す.
  • Applied Optics 46 (23) 5902 -5911 2007年08月10日 [査読無し][通常論文]
  • Daisuke Ishikawa, Atsushi Okamoto, Satoshi Honma, Terumasa Ito, Kohei Shimayabu, Kunihiro Sato Optical Review 14 (4) 246 -251 2007年07月 [査読無し][通常論文]
     
    In this paper, we propose all-optical multifunctional logic gates for image information using photorefractive (PR) two-wave mixing. The optical setup is simply configured compared with the other all-optical logic gates for image information. The XOR-, OR-, and AND-operation are all-optically performed in the same optical setup through the transitional response of the PR medium. One can switch these logic operations simply by means of the on-off control of the signal and the pump beam illumination. We analyze the spatial distribution of beam intensity in these logic gates using a finite-difference beam propagation method (FD-BPM) and the crosstalk between adjoining pixels is examined from the result. We also experimentally verify that the XOR-, OR-, and AND-gates are realized in the same optical setup. © 2007 The Optical Society of Japan.
  • Terumasa Ito, Atsushi Okamoto, Kunihiro Sato Optical Review 14 (4) 219 -223 2007年07月 [査読無し][通常論文]
     
    We present a novel numerical model for analyzing shift margin in spatial spread-spectrum (SSS) multiplexing, in which the spatial phase of signal beams, not in reference beams, is modulated and demodulated by a random diffuser to multiplex holograms. The shift margin is determined not by the Bragg effect of a thick hologram, but mainly by the phase correlation property of the diffuser used. In our model, we simulate signal data patterns and a smooth rough surface of a diffuser using oversampling and zero-padding, which allows us to cover crosstalk calculations and direct bit-errors calculations, with a fine shift resolution and a wide diffusion angle range. Calculation results revealed that the practical shift margin that ensures a signal to noise ratio more than 3.0 and a bit-error rate less than 10-2 is in the range of 0.3ωeff-0.5ωeff, where ωeff is the effective autocorrelation length of the diffuser transmission function. This model will be helpful in designing the optimum random diffuser profile for SSS multiplexing. © 2007 The Optical Society of Japan.
  • Terumasa Ito, Atsushi Okamoto, Kunihiro Sato OPTICAL REVIEW 14 (4) 219 -223 2007年07月 [査読無し][通常論文]
     
    We present a novel numerical model for analyzing shift margin in spatial spread-spectrum (SSS) multiplexing, in which the spatial phase of signal beams, not in reference beams, is modulated and demodulated by a random diffuser to multiplex holograms. The shift margin is determined not by the Bragg effect of a thick hologram, but mainly by the phase correlation property of the diffuser used. In our model, we simulate signal data patterns and a smooth rough surface of a diffuser using oversampling and zero-padding, which allows LIS to cover crosstalk calculations and direct bit-errors calculations. with a fine shift resolution and a wide diffusion angle range. Calculation results revealed that the practical shift margin that ensures a signal to noise ratio more than 3.0 and a bit-error rate less than 10(-2) is in the range of 0.3 omega(eff)-0.5 omega(eff), where omega(eff) is the effective autocorrelation length of the diffuser transmission function. This model will be helpful in designing the optimum random diffuser profile for SSS multiplexing. (c) 2007 The Optical Society of Japan.
  • Daisuke Ishikawa, Atsushi Okamoto, Satoshi Honma, Terumasa Ito, Kohei Shimayabu, Kunihiro Sat OPTICAL REVIEW 14 (4) 246 -251 2007年07月 [査読無し][通常論文]
     
    In this paper, we propose all-optical multifunctional logic gates for image information using photorefractive (PR) two-wave mixing. The optical setup is simply configured compared with the other all-optical logic gates for image information. The XOR-, OR-, and AND-operation are all-optically performed in the same optical setup through the transitional response of the PR medium. One can switch these logic operations simply by means of the on-off control of the signal and the pump beam illumination. We analyze the spatial distribution of beam intensity in these logic gates using a finite-difference beam propagation method (FD-BPM) and the crosstalk between adjoining pixels is examined from the result. We also experimentally verify that the XOR-, OR-, and AND-gates are realized in the same optical setup. (c) 2007 The Optical Society of Japan.
  • Atsushi Okamoto, Satoshi Honma, Shunsuke Uemura, Terumasa Ito OPTICS AND LASER TECHNOLOGY 39 (4) 881 -884 2007年06月 [査読無し][通常論文]
     
    This paper presents a new proposal for a mutually pumped phase conjugate mirror (MPPCM) using cross polarization. In the cross polarized MPPCM, two light beams, whose polarizations are orthogonal to each other, incident on a photorefractive crystal, Causing photorefractive interaction to generate phase conjugate waves with an orthogonal polarization to an incident beam. The use of Ar+ laser and BaTiO3 crystal in an experiment for the cross polarized MPPCM found that diffraction efficiency for an extraordinary beam is about 20%. As opposed to a conventional parallel polarized MPPCM in which the use of a beam splitter is required to separate a diffraction beam, the cross polarized MPPCM can efficiently extract phase conjugate waves by means of a polarized beam splitter, demonstrating the advantage of substantially improved efficiency. (c) 2006 Elsevier Ltd. All rights reserved.
  • Takayuki Sano, Atsushi Okamoto, Kunihiro Sato, Masatoshi Bunsen JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 46 (6B) 3822 -3827 2007年06月 [査読無し][通常論文]
     
    A novel selective erasure method for multiplexed holograms in a photorefractive crystal using a phase conjugator is presented. In this method, the pi-phase shift effect on the diffracted beam due to the photorefractive effect is used. There is a pi-phase shift between the interference pattern formed by the reading and diffraction beams, and that formed in the recording process. By returning the reading and reconstructed beams to a recording medium with a phase conjugator, the hologram can be selectively erased in parallel with the readout. Therefore, a dynamic selective erasure can be realized without requiring the accurate alignment of the selective erasure beams. The calculations using coupled-wave equations and experiment results demonstrate the implementability of our method. Furthermore, we analytically determine the requisite conditions of incident beams in the selective erasure process for the reduction of the decay of other multiplexed holograms.
  • Terumasa Ito, Atsushi Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 46 (6B) 3816 -3821 2007年06月 [査読無し][通常論文]
     
    In this paper, we propose a new parallel hologram copying system in which multiplexed holograms are coherently copied from a master medium to a copy medium. The diffraction efficiency in spatial spread-spectrum multiplexing, which is a type of phase multiplexing based on phase modulation onto signals, can be significantly enhanced by coherent parallel copying. We theoretically and experimentally showed that the diffraction efficiency of M multiplexed holograms can be increased up to 1/M of that of a single hologram, which is an improvement by a factor of M compared with the 1/M-2 formula in conventional multiplexing systems.
  • Masatoshi Bunsen, Hirosuke Furuta, Atsushi Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 46 (6B) 3858 -3861 2007年06月 [査読無し][通常論文]
     
    A selective erasure/update method of multiplexed photorefractive and photopolymer holograms by use of the double Mach-Zehnder (DMZ) interferometric arrangement is proposed. The DMZ arrangement is used as the optical phase-control device for holographic recording/erasure/update operations, which can produce a pair of pi-phase-shifted interference patterns with a simple optical setup. We intend to erase the holograms recorded in not only the inherently rewritable photorefractive crystal but also the photopolymer material generally used for the write-once (i.e., unerasable) holographic recording. It is experimentally confirmed that our method can erase the write-once type photopolymer holograms as well as the photorefractive holograms, although there will be a certain degree of restriction on the rewrite cycles limited by the monomer density, the degree of multiplexing and so on.
  • Masatoshi Bunsen, Hirosuke Furuta, Atsushi Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 46 (6B) 3858 -3861 2007年06月 [査読無し][通常論文]
     
    A selective erasure/update method of multiplexed photorefractive and photopolymer holograms by use of the double Mach-Zehnder (DMZ) interferometric arrangement is proposed. The DMZ arrangement is used as the optical phase-control device for holographic recording/erasure/update operations, which can produce a pair of pi-phase-shifted interference patterns with a simple optical setup. We intend to erase the holograms recorded in not only the inherently rewritable photorefractive crystal but also the photopolymer material generally used for the write-once (i.e., unerasable) holographic recording. It is experimentally confirmed that our method can erase the write-once type photopolymer holograms as well as the photorefractive holograms, although there will be a certain degree of restriction on the rewrite cycles limited by the monomer density, the degree of multiplexing and so on.
  • Atsushi Okamoto, Satoshi Honma, Shunsuke Uemura, Terumasa Ito OPTICS AND LASER TECHNOLOGY 39 (4) 881 -884 2007年06月 [査読無し][通常論文]
     
    This paper presents a new proposal for a mutually pumped phase conjugate mirror (MPPCM) using cross polarization. In the cross polarized MPPCM, two light beams, whose polarizations are orthogonal to each other, incident on a photorefractive crystal, Causing photorefractive interaction to generate phase conjugate waves with an orthogonal polarization to an incident beam. The use of Ar+ laser and BaTiO3 crystal in an experiment for the cross polarized MPPCM found that diffraction efficiency for an extraordinary beam is about 20%. As opposed to a conventional parallel polarized MPPCM in which the use of a beam splitter is required to separate a diffraction beam, the cross polarized MPPCM can efficiently extract phase conjugate waves by means of a polarized beam splitter, demonstrating the advantage of substantially improved efficiency. (c) 2006 Elsevier Ltd. All rights reserved.
  • Applied Optics 46 (13) 2443 -2452 2007年05月01日 [査読無し][通常論文]
  • Atsushi Okamoto, Akifumi Mita, Hisatoshi Funakoshi, Kiyoshi Moritake, Takayuki Sano JOURNAL OF MODERN OPTICS 54 (4) 599 -609 2007年03月 [査読無し][通常論文]
     
    We propose a new all-optical encryption technique, which is a two-wave encryption method, and discuss security and holographic memory using this technique. Unlike the DRPE method, this technique is characterized by its ability to reduce output intensity for unauthorized memory access, along with the property to output a recorded white-noise image. Thus, the monitoring of output intensity achieves easy detection of unauthorized access. According to our numerical simulation, a particularly significant difference can be found in Output intensity, with a correlation coefficient of 20% or under between a key using unauthorized access and a compatible key to find detection sensitivity of unauthorized access. Robustness can be readily improved by increasing key length, and the probability was observed to be 10(-6) or under on identifying a randomly generated key with a key length of about 32 x 32 for the compatible key, even though the key length is too small. It is shown experimentally that the use of a compatible key reproduced a clear original image, but unauthorized key-based reproduction reduced output strength to approximately 1/20.
  • Atsushi Okamoto, Akifumi Mita, Hisatoshi Funakoshi, Kiyoshi Moritake, Takayuki Sano JOURNAL OF MODERN OPTICS 54 (4) 599 -609 2007年03月 [査読無し][通常論文]
     
    We propose a new all-optical encryption technique, which is a two-wave encryption method, and discuss security and holographic memory using this technique. Unlike the DRPE method, this technique is characterized by its ability to reduce output intensity for unauthorized memory access, along with the property to output a recorded white-noise image. Thus, the monitoring of output intensity achieves easy detection of unauthorized access. According to our numerical simulation, a particularly significant difference can be found in Output intensity, with a correlation coefficient of 20% or under between a key using unauthorized access and a compatible key to find detection sensitivity of unauthorized access. Robustness can be readily improved by increasing key length, and the probability was observed to be 10(-6) or under on identifying a randomly generated key with a key length of about 32 x 32 for the compatible key, even though the key length is too small. It is shown experimentally that the use of a compatible key reproduced a clear original image, but unauthorized key-based reproduction reduced output strength to approximately 1/20.
  • Hiroyuki Nihei, Atsushi Okamoto PHOTON COUNTING APPLICATIONS, QUANTUM OPTICS, AND QUANTUM CRYPTOGRAPHY 6583 656830Q.1-656830Q.8 2007年 [査読無し][通常論文]
     
    We have demonstrated the coherent control of photonic bandgap (PBG) devices composed of a three-level atom embedded in three-dimensional PBG structures, which enables us to strongly suppress the loss of quantum information not only during its storage but also during its processing. We find that this ultralow-loss optical quantum information processing can be realized by generating the upper atomic level splitting inside the PBG and by tuning one of the split levels to a dark line in the emission spectrum (zeros in the spectrum at certain values of the emitted photon frequency). Furthermore, we show that the coherent control may provide a basis for the universal quantum logic gate operation in quantum computing.
  • Hiroyuki Nihei, Atsushi Okamoto OPTOMECHATRONIC MICRO/NANO DEVICES AND COMPONENTS III 6717 671703.1-671703.8 2007年 [査読無し][通常論文]
     
    We have demonstrated the coherent control of nanoscaleobjects (such as quantum dots) embedded in photonic crystals, which provides a basis for a one-qubit phase rotation gate that is one of the universal quantum logic gates for quantum information processing. In this demonstration, the quantum electrodynamics of the atomic system is calculated by the Schrodinger equation. Using the results of the calculation, the quantum electrodynamics is graphically represented by a Bloch sphere. This shows that the quantum state is rotated on the Bloch sphere, and this rotation is stopped or started, depending on the laser phase, which can act as a one-qubit phase rotation gate.
  • Terumasa Ito, Atsushi Okamoto, Nobuhiro Takahashi, Takayuki Sano OPTICAL DATA STORAGE 2007 6620 66201B.1-66201B.7 2007年 [査読無し][通常論文]
     
    Copying speed is an important characteristic for optical read-only memory (ROM) replication systems. The copying speed of holographic ROM replication is, however, limited by small energy efficiency of the optical system due to the small diffraction efficiency of multiplexed holograms. In this paper we propose new holographic ROM replication systems with a photorefractive amplifier, and analyze the speed gain performance. We improve energy efficiency significantly and speed up replication by amplifying weak diffraction signal beams using photorefractive wave mixing. Our new theory and numerical calculations revealed that achievable speed gain can be evaluated from only a single dimensionless parameter that is the product of the three as follows: (i) the pump beam intensity ratio in the amplifier, (ii) the ratio of the photopolymer and photorefractive sensitivities, and (iii) the dynamic range per hologram of the copy medium. In current holographic recording systems, a practical copying speed gain of more than 10 is achievable with currently available photorefractive materials.
  • Analysis of composite interpage crosstalk in shift multiplexing
    IWHM 2007 Digests, 1st International Workshop on Holographic Memories 2007 no.26p13 2007年 [査読無し][通常論文]
  • Improvement of holographic recording configuration for data page rewriting
    Technical Digest of International Symposium on Optical Memory 2007 (ISOM’07) no. We-J-01 2007年 [査読無し][通常論文]
  • Targeted control of a quantum dot in photonic crystals for a nanoscale optical memory
    Technical Digest of International Symposium on Optical Memory 2007 (ISOM’07) no. We-I P05 2007年 [査読無し][通常論文]
  • Decay Reduction of Multiplexed Holograms on Selective Erasure by Amplified Phase Conjugate Beams
    Technical Digest of International Symposium on Optical Memory 2007 (ISOM’07) no.We-J-18 2007年 [査読無し][通常論文]
  • Security Improvement by Multiplexing Dummy Data for Optical Random Phase Encryption
    Technical Digest of International Symposium on Optical Memory 2007 (ISOM’07) no.We-J-21 2007年 [査読無し][通常論文]
  • Improvement in copying speed and diffraction efficiency of holographic ROMs by photorefractive amplification and coherent parallel copying
    Technical Digest of International Symposium on Optical Memory 2007 (ISOM’07) no.Th-K-08 2007年 [査読無し][通常論文]
  • The 7th Pacific Rim Conference on Lasers and Electro-optics (CLEO/Pacific Rim 2007) no.ThP_092 2007年 [査読無し][通常論文]
  • Intrapage Crosstalk in One-beam Holographic Recording System using a Blazed Grating
    The 7th Pacific Rim Conference on Lasers and Electro-optics (CLEO/Pacific Rim 2007) no.ThH1-3 2007年 [査読無し][通常論文]
  • Time-domain differential detection using photorefractive two-wave mixing in phase-only holographic data storage system,
    The 7th Pacific Rim Conference on Lasers and Electro-optics (CLEO/Pacific Rim 2007) no.ThP_091 2007年 [査読無し][通常論文]
  • ITO Terumasa, OKAMOTO Atsushi, SATO Kunihiro Applied Optics 46 (23) 5902 -5911 2007年 [査読無し][通常論文]
  • All-optical tunable wavelength filter using photorefractive material
    Technical Digest of 12th Optoelectronics and Communications Conference (OECC2007) no.10E1-4 2007年 [査読無し][通常論文]
  • Apodization of photorefractive transmission grating for wavelength filter
    Technical Digest of 12th Optoelectronics and Communications Conference (OECC2007) no.12E2-5 2007年 [査読無し][通常論文]
  • All-optical interconnection for two-dimensional data using photorefractive organic film
    Technical Digest of 12th Optoelectronics and Communications Conference (OECC2007) no.11P-32 2007年 [査読無し][通常論文]
  • Optical Parallel Interconnects Using Organic Photorefractive Polymer
    Technical Digest of 12th Optoelectronics and Communications Conference (OECC2007) no.11P-34 2007年 [査読無し][通常論文]
  • ITO Terumasa, OKAMOTO Atsushi Japanese Journal of Applied Physics 46 (6B) 3816 -3821 2007年 [査読無し][通常論文]
  • ITO Terumasa, OKAMOTO Atsushi, FUNAKOSHI Hisatoshi, SATO Kunihiro Applied Optics 46 (13) 2443 -2452 2007年 [査読無し][通常論文]
  • High-speed holographic ROM replication systems with two-wave and four-wave photorefractive amplifier
    Technical Digest of Optical Data Storage 2007 (ODS2007) no.TuD2 2007年 [査読無し][通常論文]
  • Shugo Kano, Atsushi Okamoto, Yoshihisa Takayama, Kunihiro Sato NONLINEAR OPTICS AND APPLICATIONS II 6582 65821U1-65821U9 2007年 [査読無し][通常論文]
     
    We propose a new LD-fiber-coupling-method for bidirectionally-pumped erbium-doped fiber amplifier (EDFA) using two mutually-pumped phase-conjugate mirrors (MPPCMs). MPPCM is formed by two mutually incoherent beams in photorefractive crystal (PRC) and can convert each incident beam into each phase-conjugate beam of them. Owing to mode conversion by phase-conjugate characteristics, the coupling loss due to mode mismatching between a pump beam and a fiber is improved. Therefore, precision lens and lensed fiber for mode matching are not required. Additionally, because photorefractive index gratings that compose a MPPCM are rewritable in real time, MPPCM can dynamically adapt to a variety of system error factors, such as misalignment of components, mode conversion generated by LDs or fibers with defects. In our system, the overall coupling efficiency of pump beams is mainly determined by diffraction efficiency of MPPCMs that depends on the photorefractive coupling strength and the intensity ratio of two incident beams. However, achievable diffraction efficiency in this system is restricted by optical loss between two MPPCMs. This is because the transmitted pump beams passing through the EDF are reused for forming the opposite MPPCM. To achieve a high signal amplification gain, absorption loss of pump beam powers in the EDF is unavoidable. Therefore, we analytically and experimentally evaluate the acceptable loss between two PRCs to form both MPPCMs.
  • Tunable optical filter for wavelength division multiplexing using photorefractive planar waveguide
    Proceedings of SPIE 6582-63 65821S1-65821S9 2007年 [査読無し][通常論文]
  • Splice of photonic crystal fibres by use of double phase-conjugate mirror
    Proceedings of SPIE 6588-38 6588131 -6588138 2007年 [査読無し][通常論文]
  • Optics & Laser Technology 38 (8) 604 -613 2006年11月 [査読無し][通常論文]
  • H Funakoshi, A Okamoto OPTICS AND LASER TECHNOLOGY 38 (8) 604 -613 2006年11月 [査読無し][通常論文]
     
    We demonstrate long-term readout of a binarized image with a dynamic refreshment technique by mutually pumped phase conjugate mirrors (MPPCMs). Long-term continuous readout without any fixing technique can be achieved by the refreshment with image-bearing beam resonance between the phase conjugate mirrors. Our technique additionally offers image binarization by intensity thresholding of MPPCM without any external image processing systems. In this paper, we show grayscale-to-binary conversion as well as long-term readout can be realized by adjusting the appropriate incident beam intensities and the coupling strength of crystals. We perform recording and retrieving experiment with barium titanate crystals and demonstrate the binarized image can be reconstructed over 10 min in the double MPPCM configuration. (C) 2005 Elsevier Ltd. All rights reserved.
  • Applied Optics 45 (27) 7035 -7042 2006年09月20日 [査読無し][通常論文]
  • T Ito, A Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 45 (2B) 1270 -1276 2006年02月 [査読無し][通常論文]
     
    A new recording method called spatial spread-spectrum (SSS) multiplexing, which is particularly suitable for holographic disc recording, is proposed. Multiplexing holograms by phase modulation and demodulation onto the signal beams themselves (not onto reference beams) provides a new degree of freedom in the design of holographic storage systems, thereby making it possible to improve storage density by combining with other multiplexing methods. In our newly proposed recording geometry with spatial filtering, uncorrelated noise coming from undesired pages can be efficiently deflected away from a detector. Calculations show that the theoretically achievable multiplicity of the SSS recording system with spatial filtering is improved up to 70 when the numerical aperture (NA) of the signal beam is 0.1.
  • T Ito, A Okamoto JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 45 (2B) 1270 -1276 2006年02月 [査読無し][通常論文]
     
    A new recording method called spatial spread-spectrum (SSS) multiplexing, which is particularly suitable for holographic disc recording, is proposed. Multiplexing holograms by phase modulation and demodulation onto the signal beams themselves (not onto reference beams) provides a new degree of freedom in the design of holographic storage systems, thereby making it possible to improve storage density by combining with other multiplexing methods. In our newly proposed recording geometry with spatial filtering, uncorrelated noise coming from undesired pages can be efficiently deflected away from a detector. Calculations show that the theoretically achievable multiplicity of the SSS recording system with spatial filtering is improved up to 70 when the numerical aperture (NA) of the signal beam is 0.1.
  • 5th 213 -214 2006年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto PHOTONIC CRYSTAL MATERIALS AND DEVICES III (I.E. V) 6182 61821B.1-61821B.8 2006年 [査読無し][通常論文]
     
    We demonstrate the coherent control of the excited states of the atom embedded in a photonic band gap (PBG) structure by means of a Rabi oscillation. In this demonstration, we show that the atomic decay is strongly suppressed not only during the Rabi oscillation but also during switching process to the final steady state. This switching is achieved by eliminating one of localized field modes arising from the localization of the emitted photon in the vicinity of the atom due to the PBG, where the suppression of the atomic decay during the switching is facilitated by achieving this elimination not outside the PBG but inside the PBG. Such a coherent control of excited states without the atomic decay suggests the possibility of extending the atomic system for quantum computing to act as nearly lossless.
  • 5th 187 -188 2006年 [査読無し][通常論文]
  • All-optical XOR-, OR-, and AND-Gates using Photorefractive Two-Wave Mixing
    5th International Conference of Optics-photonics Design & Fabrication (ODF’06) Technical Digest no. 7PS4-04 2006年 [査読無し][通常論文]
  • Shift margin of a random diffuser in spatial spread-spectrum multiplexing
    5th International Conference of Optics-photonics Design & Fabrication (ODF’06) Technical Digest no.7PS3-06 2006年 [査読無し][通常論文]
  • Selective erasure of photorefractive and photopolymer holograms for rewriteable and secure data storage
    Technical Digest of International Symposium on Optical Memory 2006 (ISOM 2006) no.Th-I-43 2006年 [査読無し][通常論文]
  • Elimination of edge enhancement on hologram refresh system using two photorefractive crystals
    Technical Digest of International Symposium on Optical Memory 2006 (ISOM 2006) no.Th-I-30 2006年 [査読無し][通常論文]
  • Reduction of decay of multiplexed holograms in selective erasure using phase conjugate mirror
    Technical Digest of International Symposium on Optical Memory 2006 (ISOM 2006) no.Th-I-31 2006年 [査読無し][通常論文]
  • One-beam holographic recording using a blazed grating
    Technical Digest of International Symposium on Optical Memory 2006 (ISOM 2006) no.Th-I-45 2006年 [査読無し][通常論文]
  • Coherent parallel copying of holograms recorded by spatial spread-spectrum multiplexing
    Technical Digest of International Symposium on Optical Memory 2006 (ISOM2006) no.Mo-D-07 2006年 [査読無し][通常論文]
  • Shift-phase code multiplexing technique for holographic memory
    Technical Digest of International Symposium on Optical Memory 2006 (ISOM 2006) no.Th-I-44 2006年 [査読無し][通常論文]
  • BUNSEN Masatoshi, FURUTA Hirosuke, OKAMOTO Atsushi Applied Optics 45 (27) 7035 -7042 2006年 [査読無し][通常論文]
  • Estimation of crosstalk in holographic optical interconnection with shift-phase code multiplexing
    Technical Digest of 11th Optoelectronics and Communications Conference (OECC2006) no.5E3-2 2006年 [査読無し][通常論文]
  • Optical interconnection with photorefractive connection module by using polymeric material
    Technical Digest of 11th Optoelectronics and Communications Conference (OECC2006) no.4P-8 2006年 [査読無し][通常論文]
  • All-optical logic gates using photorefractive two-wave mixing for two-dimensional information processing
    Technical Digest of 11th Optoelectronics and Communications Conference (OECC2006) no.6B2-3 2006年 [査読無し][通常論文]
  • Ultra low-less coherent control of excited atomic states in photonic bandgap
    Technical Digest of 11th Optoelectronics and Communications Conference (OECC2006) Post Deadline Paper 2006年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto PHOTONIC CRYSTAL MATERIALS AND DEVICES III (I.E. V) 6182 61821B 2006年 [査読無し][通常論文]
     
    We demonstrate the coherent control of the excited states of the atom embedded in a photonic band gap (PBG) structure by means of a Rabi oscillation. In this demonstration, we show that the atomic decay is strongly suppressed not only during the Rabi oscillation but also during switching process to the final steady state. This switching is achieved by eliminating one of localized field modes arising from the localization of the emitted photon in the vicinity of the atom due to the PBG, where the suppression of the atomic decay during the switching is facilitated by achieving this elimination not outside the PBG but inside the PBG. Such a coherent control of excited states without the atomic decay suggests the possibility of extending the atomic system for quantum computing to act as nearly lossless.
  • Efficient Pump Beam Coupling in EDFA with Two Mutually Pumped Phase Conjugate Mirrors
    Proc. SPIE(Photonics Europe 2006) 6193-40 61930F 2006年 [査読無し][通常論文]
  • Optical Intersatellite Data Transmission with Phase Conjugate Mirror for Formation Flying
    Proc. SPIE(Photonics Europe 2006) 6187-40 618715 2006年 [査読無し][通常論文]
  • A Okamoto, T Ito, M Bunsen, Y Takayama JOURNAL OF MODERN OPTICS 52 (17) 2453 -2465 2005年11月 [査読無し][通常論文]
     
    The optical system, consisting of two photorefractive memories and a shutter-less optical feedback circuit, will be demonstrated to function as data mirroring. This function is known to automatically detect the data dropout and restore data, using unimpaired data in another memory, in the event that part or all of the data in either of them were lost for some reason. This memory system also can cope with a damaged hologram, a result of reading beams, which is a disadvantage of rewritable photorefractive memory, to ensure non-destructive holographic reading. It can be achieved by using no electronic circuits or mechanical structures; our optical experimental method in particular obtains this basic action.
  • H Funakoshi, A Okamoto, K Sato JOURNAL OF MODERN OPTICS 52 (11) 1511 -1527 2005年07月 [査読無し][通常論文]
     
    We demonstrate a long-term continuous readout of a two-dimensional image in a photorefractive holographic memory with a BaTiO3 crystal. A considerable extension of reading time is achieved by use of a hologram sustainment technique with an optical feedback circuit. Hologram rewritings by the simultaneous illumination of the reading beam and the feedback beam, which is incident on a crystal from the opposite direction to the reading beam, contribute to all-optical hologram sustainment without any. xing technique. In this paper, the effectiveness of the hologram sustainment technique is explained by the analysis of the temporal property of the amplitude of the index grating in a crystal. By calculating the temporal properties of the reconstructed beam intensity, we reveal the feedback rate and the coupling strength for high output efficiency. We perform an experiment on two-dimensional image reading and writing with a 45 degrees cut BaTiO3 crystal and show that a recorded image can be reconstructed over 20 min without critical image degradation whereas a reconstructed image fades away within 20 s in the conventional readout technique.
  • S Hondo, A Okamoto, K Sato, S Honma OPTOELECTRONIC DEVICES AND INTEGRATION, PTS 1 AND 2 5644 (Pt.2) 549 -556 2005年 [査読無し][通常論文]
     
    Recently the scheme of bi-directional optical communication with a mutual-pumped phase conjugate mirror (MPPCM) has attracted attention. Bi-directional communication enables the integration of devices because input port and output port can be shared. We propose a new design for an all-optical bi-directional interconnection with the double MPPCMs. This interconnection is composed of two photorefractive crystals and a polarized beam splitter which is located between the two crystals. The bi-directional connection is formed via two MPPCMs produced by illumination of the signal beams and the control beam. The wiring pattern can be reconfigured flexibly by changing the spatial distribution of the control beam without any adjustment of the signal beams. It is possible to combine and divide the optical pass of the signal beam and the control beam by using polarized beam splitter without loss because the signal beams and the control beam are orthogonal polarized. In addition, the signal beams transmitting through the two crystals enhance the MPPCMs efficiently under the appropriate condition. After buildup of MPPCMs, the connection is maintained without consecutive illumination of the control beam. Therefore self-holding is achieved and it enables the interconnection with lower power consumption. In this paper, we analyze the optimum intensity ratio of the control beam for the signal beam in order to shorten the time for establishment of connection. Moreover, as a basic experiment.. we confirm that the connection can be maintained by two MPPCMs after cutoff of the control beam by using a BaTiO3 crystals and an Ar+ laser.
  • Kazumasa Kori, Atsushi Okamoto, Yoshihisa Takayama, Masatoshi Bunsen, Hisatoshi Funakoshi, Terumasa Ito Proceedings of SPIE - The International Society for Optical Engineering 5642 487 -496 2005年 [査読無し][通常論文]
     
    The purpose of this study is to apply a free-space optical interconnection to a reconfigurable board-to-board connection where the wiring patterns connecting boards are optically formed without electrical-optical conversion. We regard a photorefractive bi-directional connection module (PBCM) based on a mutually pumped phase conjugate mirror as a key device to construct such a connection network and employ PBCMs at input/output interfaces of each board. Although optical behaviors of PBCM are influenced by the exposure conditions, we especially focus on the diameter of beams illuminating photorefractive media placed inside PBCM so as to find some geometrical restrictions hi a design of networking system. Through numerical analyses, we show a sample configuration of PBCM for the board-to-board interconnection and present a conceptual design of input/output interface.
  • Atsushi Okamoto, Hisatoshi Funakoshi, Masatoshi Bunsen, Akinori Nishio Proceedings of SPIE - The International Society for Optical Engineering 5642 599 -608 2005年 [査読無し][通常論文]
     
    By irradiating alternative external light into the system with four-wave mixing in photorefractive polymers, the restriction on the generation of a phase conjugate beam or diffracted light will be demonstrated in this experiment. In addition, in order to verify the use of a two-dimensional array for simultaneous switching, the elimination of only part of diffraction grating recorded will be experimentally conducted.
  • Kazuhiro Harasaka, Atsushi Okamoto, Masatoshi Bunsen, Michiharu Yamamoto Proceedings of SPIE - The International Society for Optical Engineering 6050 60500V.1-60500V.8 2005年 [査読無し][通常論文]
     
    We propose an optically controllable device Photorefractive Connection Module (PRCM) for free-space optical interconnection between boards. The optical signal composed of a large number of spatially divided channels passes through the photorefractive material which is core of PRCM. In the photorefractive material, diffraction gratings are induced only where the control beam and the pump beam are illuminated. The signal beams in desired spatial channels can be diffracted by setting an appropriate pattern of the control beam and extracted by separating from the control beam with a beam splitter. In this study, we use organic photorefractive polymer PATPD as the photorefractive material. Diffraction efficiency of PATPD is comparable with thick inorganic crystals although the thickness of PATPD is less than 1/10 of these crystals. Thin gratings have a large advantage for PRCM because the thickness of the gratings causes large crosstalk between spatial channels. In addition, the constraint of phase matching is reduced because the phase mismatch is proportional to the thickness of the material. The decrease of the phase mismatch provides large allowance for misalignment of incident angle of beams therefore it becomes easy to adjust incident angles. We reveal the relation of diffraction efficiency to angular difference of PATPD by analysis and experiment. Diffraction efficiency decreases by half at the difference of 0.5°, which is about ten times larger than that of thick crystals. We demonstrate that it is possible to extract the signal beams in desired channels and reconfigure the extraction pattern according to optical control by using PATPD.
  • Terumasa Ito, Atsushi Okamoto, Masatoshi Bunsen Proceedings of SPIE - The International Society for Optical Engineering 6050 605009.1-605009.8 2005年 [査読無し][通常論文]
     
    Volume holographic recording is a promising solution for next-generation optical disc storage that has a high capacity more than 1 TB. This huge capacity is achieved by superimposing many holograms, each of which has millions of bits, at the same recording spot. We proposed a new technique, Spatial Spread Spectrum (SSS) multiplex recording in Ref 1. Unlike conventional multiplex holography based on Bragg effect of thick holograms, our technique utilizes spatial phase modulation and demodulation of the signal beam itself with a random diffuser to address the multiplexed page data. SSS multiplexing is additionally combined with other multiplexing methods, and provides further improvement of the total capacity of holographic storage. In this paper we experimentally verify the basic recording and readout feasibility, and investigate the shift selectivity and the aligning margin of the SSS holographic recording that are an important factor to determine the tolerance against vibration. It is shown that a clear 2-dimensional image is successfully reconstructed from the hologram even in the case the central part of the diffused signal beam is blocked in recording, and that a sharp shift selectivity about 5 μm was obtained by a diffuser with a diffusion angle of 15 degree, and the aligning margin for a sufficient SNR was approximately 1 μm.
  • Takayuki Sano, Atsushi Okamoto, Kunihiro Sato, Masatoshi Bunsen Proceedings of SPIE - The International Society for Optical Engineering 6050 60500X.1-60500X.8 2005年 [査読無し][通常論文]
     
    In this paper, we propose a selective erasure method for multiplexed holograms in a photorefractive crystal using a phase conjugate mirror (PCM). In this method, for the accurate selective erasure, we use π phase shift between the relative phase of the diffracted beam to the transmitted beam by the hologram in photorefractive crystal and the relative phase of the object beam to reference beam in recording process by setting the direction of c-axis to the appropriate direction. In the selective erasure process, the diffracted beam and the transmitted beam by the original hologram in main memory are returned to main memory by PCM. These returned beams automatically propagate through the strictly same pass as the diffracted beam and the transmitted beam. Furthermore, by these returned beams, the π-phase shifted hologram is overwritten on the original hologram by setting c-axis of main memory to the appropriate direction. Therefore, the π-phase shifted hologram is automatically overwritten on the strictly same position as the original hologram without the high precise alignment and the original hologram is selectively erased. We perform the analysis and the experiment on selective erasure and demonstrate that one of the multiplexed holograms is selectively erased with our method.
  • 「相互励起型4波混合を用いた位相共役発生に関する入射強度比の最適化と位相共役変換効率の多値特性」
    電子情報通信学会論文誌C Vol.J88-C (2) 91 -98 2005年 [査読無し][通常論文]
  • 「相互励起型位相共役鏡による揮発性ホログラムの全光学的維持手法」
    電子情報通信学会論文誌 Vol.J88-C (4) 286 -289 2005年 [査読無し][通常論文]
  • Ito, T., Okamoto, A. and Bunsen, M.: “Shift selectivity of spatial spread-spectrum holographic recording system”, Proceedings of. SPIE(ISOT2005), Vol.6050-09(2005)**
    2005年 [査読無し][通常論文]
  • 「フォトニック結晶に埋め込まれた原子のラビ振動」
    電子情報通信学会論文誌 Vol.J88-C (11) 998 -999 2005年 [査読無し][通常論文]
  • Kaseda, H., Okamoto, A., Y. Takayama and Kato, H.: “Improvement of Coupling Efficiency between Pump Light Source and Fiber in EDFA using Mutually Pumped Phase Conjugate Mirrors”, Technical Digest of International Quantum Electronics Conference and the ・・・
    2005年 [査読無し][通常論文]
     
    Kaseda, H., Okamoto, A., Y. Takayama and Kato, H.: “Improvement of Coupling Efficiency between Pump Light Source and Fiber in EDFA using Mutually Pumped Phase Conjugate Mirrors”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers and Elector-Optics 2005 (IQEC and CLEO-PR2005), no. CThC3-P19(2005)**
  • Harasaka, K., Okamoto, A., Bunsen, M. and Yamamoto, M.: “Photorefractive Connection Module with Organic Photorefractive Polymer PATPD”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers and Electo・・・
    2005年 [査読無し][通常論文]
     
    Harasaka, K., Okamoto, A., Bunsen, M. and Yamamoto, M.: “Photorefractive Connection Module with Organic Photorefractive Polymer PATPD”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers and Elector-Optics 2005 (IQEC and CLEO-PR2005), no.CthC3-P21(2005)**
  • Muranaka, H., Okamoto, A., Uemura, S., Bunsen, M., and Nishio, A.: “Optical Image Cross Connector with Multiple-layered Photorefractive Polymers”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers・・・
    2005年 [査読無し][通常論文]
     
    Muranaka, H., Okamoto, A., Uemura, S., Bunsen, M., and Nishio, A.: “Optical Image Cross Connector with Multiple-layered Photorefractive Polymers”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers and Elector-Optics 2005 (IQEC and CLEO-PR2005), no.CThC3-P20(2005)**
  • Nihei, H. and Okamoto, A.: “Coherent control of a qubit embedded in photonic crystals using a dark line in emission spectra”, Proceedings of 12th European Conference on Integrated Optics (ECIO’05) , pp.598 (2005)**
    2005年 [査読無し][通常論文]
  • Sano, T., Okamoto, A., Sato, K. and Bunsen, M.: “Selective erasure for multiplexed holograms by using photorefractive phase-shift”, The European Conference on Lasers and Electro-Optics (CLEO Europe 2005), CC-2-WED (2005)**
    2005年 [査読無し][通常論文]
  • Ito, T. and Okamoto, A.: “Spatial spread-spectrum multiplexing for holographic data storage using random diffuser and circular spatial filter”, The European Conference on Lasers and Electro-Optics (CLEO Europe 2005), CC1-4-TUE(2005)**
    2005年 [査読無し][通常論文]
  • Harasaka, K., Okamoto, A., Bunsen, M., and Yamamoto, M.: “Experiment on signal extraction in photorefractive connection module with organic polymer PATPD”, Proceedings of. SPIE(ISOT2005), Vol. 6050-0V(2005)**
    2005年 [査読無し][通常論文]
  • Moritake, K., Okamoto, A., Funakoshi, H. and Ito, T.: “Security improvement with multiplexing for optical encryption based on cross-correlation of random phase masks”, Technical Digest of International Quantum Electronics Conference and the Pacific Ri・・・
    2005年 [査読無し][通常論文]
     
    Moritake, K., Okamoto, A., Funakoshi, H. and Ito, T.: “Security improvement with multiplexing for optical encryption based on cross-correlation of random phase masks”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers and Elector-Optics 2005 (IQEC and CLEO-PR2005), no.CTuN1-2(2005)**
  • Sano, T., Okamoto, A., Sato, K. and Bunsen, M.: “Selective erasure for multiplexed holograms in photorefractive crystal using phase conjugate mirror”, Proceedings of SPIE(ISOT2005) vol.6050-0X, (2005)**
    2005年 [査読無し][通常論文]
  • Okamoto, A., Funakoshi, H., Bunsen, M., Ito, T. and Sato, K.: “Optical security switch based on spatially phase matching in photorefractive media”, The European Conference on Lasers and Electro-Optics (CLEO Europe 2005), CC-2-WED(2005)**
    2005年 [査読無し][通常論文]
  • Ito, T. and Okamoto, A.: “Volume holographic recording with spatial spread-spectrum multiplexing technique”, Technical Digest of International Symposium on Optical Memory and Optical Data Storage Topical Meeting 2005 (ISOM/ODS2005), no.MP-20(2005)**
    2005年 [査読無し][通常論文]
  • Nihei, H. and Okamoto, A.: “Optical switching of an atomic system in photonic crystals using a dark line in emission spectra”, Technical Digest of Optoelectronics and Communications Conference (OECC2005), pp. 294-295(2005)**
    2005年 [査読無し][通常論文]
  • Bunsen, M., Okamoto, A. and Furuta, H.: “A method for selective erasure of multiplexed holograms by use of double Mach-Zehnder interferometer”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), pp.624-625 (2005)**
    2005年 [査読無し][通常論文]
  • Shiratori, T., Okamoto, A., Kori, K., and Funakoshi, H.: “All-optical Reconfigurable Waveguide with Mutually-pumped Phase Conjugate Mirrors for Free-space Optical Interconnection”, Technical Digest of 10th Optoelectronics and Communications Conference ・・・
    2005年 [査読無し][通常論文]
     
    Shiratori, T., Okamoto, A., Kori, K., and Funakoshi, H.: “All-optical Reconfigurable Waveguide with Mutually-pumped Phase Conjugate Mirrors for Free-space Optical Interconnection”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), no.7P-032(2005)**
  • Muranaka, H., Okamoto, A., Uemura, S., Bunsen, M., and Nishio, A.: “Optically Controlled Image Cross Connector with Photorefractive Polymer”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), no.7P-118(2005)**
    2005年 [査読無し][通常論文]
  • Honma, S., Matsuyama, D., Ito, T., Okamoto, A., and Muto, S.: “Optical interconnection by holographic router and movement with orthogonal phase matrix pattern”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), no.6E4-7・・・
    2005年 [査読無し][通常論文]
     
    Honma, S., Matsuyama, D., Ito, T., Okamoto, A., and Muto, S.: “Optical interconnection by holographic router and movement with orthogonal phase matrix pattern”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), no.6E4-7(2005)**
  • Ito, T., Okamoto, A., and Funakoshi, H.: “Static holographic random access memory using two photorefractive crystals”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), no.7P-069(2005)**
    2005年 [査読無し][通常論文]
  • Kaseda, H., Okamoto, A., Takayama, Y., Kato, H. and Sato, K.: “Effective coupling method between pump light source and fiber in EDFA with one mutually pumped phase conjugate mirror”, Technical Digest of 10th Optoelectronics and Communications Conferenc・・・
    2005年 [査読無し][通常論文]
     
    Kaseda, H., Okamoto, A., Takayama, Y., Kato, H. and Sato, K.: “Effective coupling method between pump light source and fiber in EDFA with one mutually pumped phase conjugate mirror”, Technical Digest of 10th Optoelectronics and Communications Conference (OECC2005), no.7P-055(2005)**
  • Okamoto, A., Terumasa Ito, Bunsen, M. and Takayama, Y.: “Fault tolerant function of dynamic refreshing holographic memory with shutter-less optical feedback circuit”, Journal of Modern Optics Vol. 52(17), pp.2453-2465 (2005)**
    2005年 [査読無し][通常論文]
  • Nihei, H. and Okamoto, A. : “Coherent control of spontaneous emission near a photonic band edge using a dark line in emission spectra”, The European Conference on Lasers and Electro-Optics (CLEO Europe 2005), CK3-4(2005)**
    2005年 [査読無し][通常論文]
  • Sano, T., Okamoto, A., Sato, K. and Bunsen, M.: “Experiment on selective erasure for multiplexed holograms by using photorefractive phase shift”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers ・・・
    2005年 [査読無し][通常論文]
     
    Sano, T., Okamoto, A., Sato, K. and Bunsen, M.: “Experiment on selective erasure for multiplexed holograms by using photorefractive phase shift”, Technical Digest of International Quantum Electronics Conference and the Pacific Rim Conference on Lasers and Elector-Optics 2005 (IQEC and CLEO-PR2005), no.CWAB3-P89(2005)**
  • 「フォトリフラクティブ結晶と二重マッハツェンダ-干渉光学系による二次元画像演算とそのXOR暗号化への応用」
    電子情報通信学会論文誌C vol.J88-C (1) 72 -73 2005年 [査読無し][通常論文]
  • Bunsen, M. and Okamoto, A.: “Theoretical and experimental studies of hologram multiplexing that uses a random wave front generated by photorefractive beam fanning”, Applied Optics, Vol.44(8), pp.1454-1463 (2005)**
    2005年 [査読無し][通常論文]
  • Funakoshi, H., Okamoto, A. and Sato, K.: “Long-term reading experiment on photorefractive holographic memory with hologram sustainment technique by optical feedback”, Journal of Modern Optics, Vol. 52(11), pp. 1511-1527 (2005)**
    2005年 [査読無し][通常論文]
  • Uemura, S., Okamoto, A. and Honma, S.: “All-optical interconnection with cross-polarized double phase conjugate mirror” Proceedings of SPIE, 5350 (Photonics West 2004): 234-242(2004).*
    2004年 [査読無し][通常論文]
  • Bunsen, M., Okamoto, A. and Sato, K. :“Photorefractive holographic memory by use of beam-fanning phenomenon in storage crystal” Proceedings of 10th Microoptics Conference (MOC’04), no.F-31:CD-ROM(2004).*
    2004年 [査読無し][通常論文]
  • T. Ito, Okamoto, A. and Sato, K. :“Compact dynamic holographic storage system using parallel phase-conjugate refreshment for multiplexed holograms” Proceedings of 10th Microoptics Conference (MOC’04), no.F-32:CD-ROM(2004).*
    2004年 [査読無し][通常論文]
  • Okamoto, A., Funakoshi, H., Moritake, K. and Bunsen, M. :“Security measures in optical devices by spatial phase matching in a photorefractive crystal” Proceedings of 10th Microoptics Conference (MOC’04), no.F-38:CD-ROM(2004).*
    2004年 [査読無し][通常論文]
  • Nihei, H. and Okamoto, A.:“Optical quantum gate using a qubit embedded in photonic bandgap structures”, 10th Microoptics Conference (MOC), H-3:CD-ROM(2004).*
    2004年 [査読無し][通常論文]
  • H. Nihei and Okamoto, A.: “Coherent control of a qubit embedded in photonic bandgap structures with high-speed switching,” Proceedings of 30th European Conference on Optical Communication (ECOC2004), 5:78-79(2004).*
    2004年 [査読無し][通常論文]
  • Funakoshi, H., Okamoto, A. and Sato, K.: “Long-term retrieving experiment on rewritable holographic memory with dynamic refreshment by mutual-pumped phase conjugator,” Proceedings of SPIE, 5636-93 (2004).*
    2004年 [査読無し][通常論文]
  • Honma, S., Muto, S. and Okamoto, A.: “All-optical interconnection with mutually pumped four-wave mixing and optimization for high-connection efficiency,” Proceedings of SPIE, 5636-108(2004).*
    2004年 [査読無し][通常論文]
  • Kori, K., Okamoto, A., Takayama, Y., Bunsen, M., Funakoshi, H. and Ito, T.: “Photorefractive bi-directional connection module with mutual-pumped phase conjugate mirror,” Proceedings of SPIE, 5642-86(2004).*
    2004年 [査読無し][通常論文]
  • Ito, T., Okamoto, A. and Funakoshi, H. :“Noise Reduced Refreshment for Dynamic Holographic Memory with Phase Conjugation in a BaTiO3 Crystal,” Proceedings of 9th Optoelectronics and Communications Conference / 3rd International Conference on Optical In・・・
    2004年 [査読無し][通常論文]
     
    Ito, T., Okamoto, A. and Funakoshi, H. :“Noise Reduced Refreshment for Dynamic Holographic Memory with Phase Conjugation in a BaTiO3 Crystal,” Proceedings of 9th Optoelectronics and Communications Conference / 3rd International Conference on Optical Internet (OECC/COIN2004), no.16E2-2: 872-873(2004).*
  • Mita, A., Okamoto, A. and Funakoshi, H.: “Effect of random phase mask on input plane in photorefractive authentic memory with two-wave encryption method,” Proceedings of SPIE, 5362 (Photonics West 2004): 61-68(2004).*
    2004年 [査読無し][通常論文]
  • Bunsen, M., Okamoto, A. and Takayama, Y.: “Hologram multiplexing with photorefractive beam-fanning speckle,” Opt. Commun., 235(1-3):41-47(2004).*
    2004年 [査読無し][通常論文]
  • 「ホトリフラクティブ相互励起型4波混合」
    電子情報通信学会論文誌C VOL.J87-C (3) 350 -351 2004年 [査読無し][通常論文]
  • Nihei, H. and Okamoto, A.: “Spontaneous emission from a three-level atom embedded in anisotropic photonic band gap structures”, Journal of Modern Optics, 51(13):1983-1998 (2004).*
    2004年 [査読無し][通常論文]
  • 「2重マッハツェンダ-干渉光学系によるスペックル多重ホログラムの選択的消去・更新手法」
    電子情報通信学会論文誌C J87-C (11) 982 -983 2004年 [査読無し][通常論文]
  • Kato, H., Okamoto, A. and Bunsen, M.: “Stabilization of Signal Beam Intensity for Fault-Tolerant Automatic Routing with Double Phase Conjugate Mirrors,” Proceedings of SPIE, 5363 (Photonics West 2004):148-155(2004).*
    2004年 [査読無し][通常論文]
  • Yagai, T., Okamoto, A., Bunsen, M.: “All-optical interconnection with photorefractive grating array for wavelength divided multiplexing signal,” Proceedings of SPIE,5350 (Photonics West 2004): 81-88(2004).*
    2004年 [査読無し][通常論文]
  • Hondo, S., Okamoto, A. and Honma, S.: “All-optical bidirectional interconnection by light-induced waveguide with double mutual-pumped phase conjugation” Proceedings of SPIE, 5363 (Photonics West 2004): 156-163(2004).*
    2004年 [査読無し][通常論文]
  • Funakoshi, H. and Okamoto, A.: “Noise reduction in photorefractive memory by double mutually pumped phase conjugate mirrors” Proceedings of SPIE, 5362 (Photonics West 2004): 99-106(2004).*
    2004年 [査読無し][通常論文]
  • Bunsen, M. and Okamoto, A.: “Hologram multiplexing method with photorefractive beam-fanning speckle,” Proceedings of SPIE,5362 (Photonics West 2004):128-135(2004).*
    2004年 [査読無し][通常論文]
  • Takayama, Y. and Okamoto, A., “Optical manipulation of multiple stable states in photorefractive four-wave mixing,” Journal of Modern Optics, 51(2): 197-208 (2004).*
    2004年 [査読無し][通常論文]
  • Kori, K., Okamoto, A., Takayama, Y. and Bunsen, M.: “All-optical Free-space Board to Board Interconnection with Photorefractive Bi-directional Connection Module,” Proceedings of 9th Optoelectronics and Communications Conference / 3rd International Conf・・・
    2004年 [査読無し][通常論文]
     
    Kori, K., Okamoto, A., Takayama, Y. and Bunsen, M.: “All-optical Free-space Board to Board Interconnection with Photorefractive Bi-directional Connection Module,” Proceedings of 9th Optoelectronics and Communications Conference / 3rd International Conference on Optical Internet (OECC/COIN2004), no.13P-46:204-205(2004).*
  • Funakoshi, H. and Okamoto, A.: “Digital Recording with Dynamic Refreshing Technique by Mutually Pumped Phase Conjugator in Photorefractive Memory,” Proceedings of Optics in Computing 2004:pp.63-64(2004).*
    2004年 [査読無し][通常論文]
  • Nihei, H. and Okamoto, A.:”All-optical rotation gates using an atom embedded in photonic bandgap structures”, Proceedings of Optics in Computing: 151-152(2004).*
    2004年 [査読無し][通常論文]
  • Hondo, S., Okamoto, A. and Honma, S.: “All-Optical Bi-Directional Interconnection with Double Mutual-Pumped Phase Conjugators by using Cross-Polarized Control Beam,” Proceedings of. Optics in Computing 2004:59-60(2004).*
    2004年 [査読無し][通常論文]
  • Moritake, K., Okamoto, A., Mita, A. and Funakoshi, H.:“Security Enhancement of Authentic Memory by Two-Wave Encryption Method with High Resolution Phase Mask,” Proceedings of Optics in Computing 2004:53-54(2004).*
    2004年 [査読無し][通常論文]
  • Ito, T., Okamoto, A., Funakoshi, H.: “Experiment on two-dimensional data restoring in fault-tolerant holographic memory” Proceedings of SPIE, 5362(Photonics West 2004): 111-118(2004).*
    2004年 [査読無し][通常論文]
  • Okamoto, A., Bunsen, M. and Funakoshi, H.: “Rewritable Holographic Memory using All-Optical Multiplexing and Nondestructive Reading Technology,” Proceedings of 9th Optoelectronics and Communications Conference / 3rd International Conference on Optical ・・・
    2004年 [査読無し][通常論文]
     
    Okamoto, A., Bunsen, M. and Funakoshi, H.: “Rewritable Holographic Memory using All-Optical Multiplexing and Nondestructive Reading Technology,” Proceedings of 9th Optoelectronics and Communications Conference / 3rd International Conference on Optical Internet (OECC/COIN2004), no.13P-110: 330-331(2004).*
  • 「ホトリフラクティブ・ビームファニング現象により生成されるランダム波面を用いたホログラム多重記録の実験」
    電子情報通信学会論文誌 C J87-C (1) 182 -183 2004年 [査読無し][通常論文]
  • Yagai, T., Okamoto, A. and Bunsen, M., “All-optical wavelength demultiplexer with photorefractive grating array”: Proceedings of SPIE, 5646-47(2004).*
    2004年 [査読無し][通常論文]
  • Hondo, S., Okamoto, A., Sato, K. and Honma, S.: “Experiment on all-optical bi-directional interconnection with double mutual pumped phase conjugate mirrors,” Proceedings of SPIE, 5644-85 (2004).*
    2004年 [査読無し][通常論文]
  • Okamoto, A., Funakoshi, H., Bunsen, M. and Nishio, A: “Optical controlled matrix switch and free-space interconnection by photorefractive polymers,” Proceedings of SPIE, 5642-109 (2004).*
    2004年 [査読無し][通常論文]
  • “自己励起型位相共役鏡の位相補正作用を用いたフォトリフラクティブメモリにおける画像再生実験”
    電子情報通信学会論文誌 C J86-C (12) 1360 -1361 2003年 [査読無し][通常論文]
  • “自由空間光通信におけるフォールトトレラント全光通信路自動切換手法”
    電子情報通信学会論文誌 C J86-C (11) 1223 -1226 2003年 [査読無し][通常論文]
  • “二つのホトリフラクティブ結晶を用いたフォールトトレラントホログラフィックメモリ”
    電子情報通信学会論文誌 C J86-C (11) 1143 -1150 2003年 [査読無し][通常論文]
  • “フォトニック結晶を用いた光メモリからの量子情報検出”
    電子情報通信学会論文誌 C J86-C (9) 997 -1006 2003年 [査読無し][通常論文]
  • ”フォトリフラクティブメモリにおける光フィードバック回路を用いた全光学的非破壊再生手法”
    電子情報通信学会論文誌 C J86-C (3) 236 -243 2003年 [査読無し][通常論文]
  • Satoshi Honma and Atsushi Okamoto: “All-optical interconnection device with photorefractive semi-linear resonator ”, IEICE Trans. Electron., vol.E86-C, no.10, pp.2103-2110 (2003-10).*
    2003年 [査読無し][通常論文]
  • M. Bunsen and A. Okamoto, “Experiment on hologram multiplexing with photorefractive beam-fanning speckle,” Proc. 5th International Conference on Transparent Optical Networks, no.Tu.P.8, pp.287-290, June 2003.*
    2003年 [査読無し][通常論文]
  • H. Funakoshi, A. Okamoto and K. Sato, “Experiment on long-term image reading in photorefractive memory with double mutually pumped phase conjugate mirrors,” Proc. 5th International Conference on Transparent Optical Networks, no.Tu.P.9, pp.291-294, June・・・
    2003年 [査読無し][通常論文]
     
    H. Funakoshi, A. Okamoto and K. Sato, “Experiment on long-term image reading in photorefractive memory with double mutually pumped phase conjugate mirrors,” Proc. 5th International Conference on Transparent Optical Networks, no.Tu.P.9, pp.291-294, June 2003.*
  • H. Kato, A. Okamoto and M. Bunsen, “Fault-tolerant automatic routing method with two photorefractive double phase conjugate mirrors,” Proc. 5th International Conference on Transparent Optical Networks, no.Tu.P.10, pp.295-298, June 2003.*
    2003年 [査読無し][通常論文]
  • Hiroyuki Nihei and Atsushi Okamoto:”Two-qubit operation of two atoms embedded in photonic crystals for optical quantum computing,” Proc. 5th International Conference on Transparent Optical Networks, no.Th.C.6, pp.212-215, June 2003.*
    2003年 [査読無し][通常論文]
  • T. Yagai, A. Okamoto K. Sato and M. Bunsen, “All-optical interconnection with photorefractive cross-polarized four-wave mixing and control beam,” Proc. 9th Microoptics Conference, no.H12, pp.170-173, Oct. 2003.*
    2003年 [査読無し][通常論文]
  • S. Hondo, A. Okamoto, S. Honma and H. Funakoshi, “All-optical bi-directional interconnection with double mutual-pumped phase conjugation,” Proc. 9th Microoptics Conference, no.H13, pp.174-177, Oct. 2003.*
    2003年 [査読無し][通常論文]
  • H. Kato, A. Okamoto and M. Bunsen, “Fault-tolerant automatic routing method with photorefractive double phase conjugate mirrors,” Proc. 9th Microoptics Conference, no.H14, pp.178-181, Tokyo, Japan, Oct. 2003.*
    2003年 [査読無し][通常論文]
  • H. Funakoshi, A. Okamoto and K. Sato, “Dynamic Refreshing Technique in Photorefractive Memory with Mutually Pumped and Self-Pumped Phase Conjugate Mirrors,” Proc. International Symposium on Optical Memory (ISOM2003), no.We-F-27, pp.122-123, Nov. 2003.*
    2003年 [査読無し][通常論文]
  • M. Bunsen and A. Okamoto “Speckle-Multiplexed Holographic Memory with Photorefractive Beam-fanning Effect,” Proc. International Symposium on Optical Memory (ISOM2003), no.We-F-57, pp.184-185, Nov. 2003.*
    2003年 [査読無し][通常論文]
  • A. Mita and A. Okamoto “High Robustness against Unlawful Access in Photorefractive Authentic Memory with Two-wave Encryption Method,” Proc. International Symposium on Optical Memory (ISOM2003), no.We-F-67, pp.204-205, Nov. 2003.*
    2003年 [査読無し][通常論文]
  • T. Ito, A. Okamoto, S. Homma and M. Toishi “All-optical Data Restoring Method for Photorefractive Holographic Memory,” Proc. International Symposium on Optical Memory (ISOM2003), no.Th-H-05, pp.242-243, Nara, Japan, Nov. 2003.*
    2003年 [査読無し][通常論文]
  • Hiroyuki Nihei and Atsushi Okamoto:”THz emission from a multifunctional active atomic device in photonic crystals,” IEEE LEOS, 5th Pacific Rim Conference on Lasers and Electro-Optics (CLEO/PR), WP-(16)-3, December 2003.*
    2003年 [査読無し][通常論文]
  • S. Uemura, A. Okamoto and S. Honma, “All-optical auto-tracking by bi-directional connection switch with cross polarized DPCM,” Proc. 9th Microoptics Conference, no.H15, pp.182-185, Oct. 2003.*
    2003年 [査読無し][通常論文]
  • 「電子デバイスの基礎」<桜庭一郎,岡本 淳>
    森北出版 2003年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto, “Spontaneous emission from a three-level atom placed in three-dimensional photonic crystals in the long-time limit”, J. Modern Optics. Vol.49, No.9, 1463-1477(2002).*
    2002年 [査読無し][通常論文]
  • ”ホトリフラクティブ相互励起型位相共役現象と結晶端面を利用したセミリニア共振器を用いた全光インタコネクション”
    電子情報通信学会論文誌 C J85-C (5) 402 -403 2002年 [査読無し][通常論文]
  • “PRCMによる2次元空間並列情報のチャネル分岐実験”
    電子情報通信学会論文誌 C J85-C (1) 35 -37 2002年 [査読無し][通常論文]
  • Mitsuru Toishi, Atsushi Okamoto, Kunihiro Sato:“Experiment on Image Data Restoring in All-Optical Fault-tolerant Holographic Memory”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Digest, 10P-80, pp346-347(2002).*
    2002年 [査読無し][通常論文]
  • Hisatoshi Funakoshi, Atsushi Okamoto and Kunihiro Sato: “Wavelength-Multiplexed Photorefractive Memory with Nondestructive Reading/Writing Technique”, Optics in Computing 2002 (OC2002), OTuD5, pp.132-134 (2002).*
    2002年 [査読無し][通常論文]
  • Satoshi Honma and Atsushi Okamoto: “Experiment on all-optical interconnection with photorefractive semi-linear resonator”, Optics in Computing 2002 (OC2002), OTuD3, pp.126-128 (2002).*
    2002年 [査読無し][通常論文]
  • Toshiya Kaino, Atsushi Okamoto and Satoshi Honma: “Fault Tolerant All-optical Router by Using Two All-optical Switches with Photorefractive Two-wave Mixing”, Optics in Computing 2002 (OC2002), OTuD2, pp.123-125 (2002).*
    2002年 [査読無し][通常論文]
  • Hiroyuki Nihei and Atsushi Okamoto: “Rotation Gate Operation in an Atomic System within Photonic Crystals for Quantum Computing”, Optics in Computing 2002 (OC2002), OTuA3, pp.68-70 (2002).*
    2002年 [査読無し][通常論文]
  • Tohru Hasegawa, Atsushi Okamoto, Takahiko Nakatagawa and Kunihiro Sato: “Experiment on Reconfigurable Interconnection for Free Space and Wavelength Division Multiplexing System”, Optics in Computing 2002 (OC2002), OMA1, pp.1-3 (2002).*
    2002年 [査読無し][通常論文]
  • Yoshihisa Takayama, Satoshi Honma, Atsushi Okamoto, “OPTICAL INVERSE FILTER FOR HOLOGRAPHIC FILTERING BY PHOTOREFRACTIVE FOUR-WAVE MIXING WITH INCOHERENT ERASURE”, Nonlinear Optics, 29, pp. 157-166(2002).*
    2002年 [査読無し][通常論文]
  • ”相互励起型位相共役鏡を用いた偏波により制御可能な2チャネルの全光クロスコネクションスイッチ”
    電子情報通信学会論文誌 C J85-C (10) 944 -945 2002年 [査読無し][通常論文]
  • Tsutomu Nakada, Atsushi Okamoto, Kunihiro Sato, “Reconfigurable free-space all-optical interconnection with beam-fanning switch in photorefractive crystal”, Optics Communications, 208, pp.69-77 (2002).*
    2002年 [査読無し][通常論文]
  • Toshiya Kaino, Atsushi Okamoto, Satoshi Honma, “Fault Tolerant All-optical Router with Photorefractive All-optical Switch”, Advanced Optical Materials and Devices(AOMD2002), P28, pp. 151(2002).*
    2002年 [査読無し][通常論文]
  • Tokonobu Mitasaki, Atsushi Okamoto, Satoshi Honma, “All-optical interconnection with wiring maintenance technique by integrated full-linear resonator”, Advanced Optical Materials and Devices(AOMD2002), p29, pp152(2002).*
    2002年 [査読無し][通常論文]
  • Satoshi Honma, Atsushi Okamoto, “All-optical bi-directional cross-connector with photorefractive double phase conjugation and control beam”, Advanced Optical Materials and Devices(AOMD2002), p30, pp153(2002).*
    2002年 [査読無し][通常論文]
  • Mitsuru Toishi, Atsushi Okamoto, Kunihiro Sato, “Dynamic Restoring Technique for Dropout Data in All-optical Fault Tolerant Holographic Memory”, Advanced Optical Materials and Devices(AOMD2002), p31, pp154(2002).*
    2002年 [査読無し][通常論文]
  • Hisatoshi Funakoshi, Atsushi Okamoto, “Photorefractive Nondestructive Memory with Kitty-Type Conjugator”, Advanced Optical Materials and Devices(AOMD2002), p32, pp155(2002).*
    2002年 [査読無し][通常論文]
  • Satoshi Honma, Atsushi Okamoto, “Bi-directional cross connector with double phase conjugator and polarization multiplexed control signal”, Proceedings of SPIE (Holography, Diffractive Optics, and Applications), 4924, pp.282-293(2002).*
    2002年 [査読無し][通常論文]
  • Akifumi Mita, Atsushi Okamoto, Noriyasu Tsuji, Masatoshi Bunsen, “ High Performance Encryption Method and All-optical Authentic Memory with Photorefractive Crystal”, Proceedings of SPIE (Advanced Optical Storage Technology), 4930, pp. 351-358(2002).*
    2002年 [査読無し][通常論文]
  • Kazumasa Kori, Atsushi Okamoto, Takahiko Nakatogawa, Kunihiro Sato, Toshiya Kaino:“Experimant on amplification of WDM and spatial multiplexed signals in Photorefractive Connection Module”, Seventh Optoelectronics and Communications Conference (OECC 200・・・
    2002年 [査読無し][通常論文]
     
    Kazumasa Kori, Atsushi Okamoto, Takahiko Nakatogawa, Kunihiro Sato, Toshiya Kaino:“Experimant on amplification of WDM and spatial multiplexed signals in Photorefractive Connection Module”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Digest, 10P-16, pp218-219(2002).*
  • T. Hasegawa, A. Okamoto, K. Sato, and M. Toishi, “Experiment on all-optical interconnection with wavelength multiplexed signal using single cat conjugator”, 3rd International Conference on Optics-photonics Design & Fabrication(ODF2002), P27, pp.149-150・・・
    2002年 [査読無し][通常論文]
     
    T. Hasegawa, A. Okamoto, K. Sato, and M. Toishi, “Experiment on all-optical interconnection with wavelength multiplexed signal using single cat conjugator”, 3rd International Conference on Optics-photonics Design & Fabrication(ODF2002), P27, pp.149-150(2002).
  • M. Bunsen, A. Okamoto, “All optical interconnection using spatial phase-address multiplexed signal and control pattern decoder”, 3rd International Conference on Optics-photonics Design & Fabrication(ODF2002), P26, pp.147-148(2002).
    2002年 [査読無し][通常論文]
  • Y. Kawata, A. Okamoto, S. Honma,“Experiment on all-optical interconnection with wavelength multiplexed signal using single cat conjugator,” 3rd International Conference on Optics-photonics Design & Fabrication(ODF2002), P28, pp.151-152(2002).
    2002年 [査読無し][通常論文]
  • Masatoshi Bunsen, Atsushi Okamoto, Kunihiro Sato, “Improvement of storage density in photorefractive disk-type memory by logical multilayer recording method”, Proceedings of SPIE Proceedings of SPIE (Advanced Optical Storage Technology),4930, pp.343-35・・・
    2002年 [査読無し][通常論文]
     
    Masatoshi Bunsen, Atsushi Okamoto, Kunihiro Sato, “Improvement of storage density in photorefractive disk-type memory by logical multilayer recording method”, Proceedings of SPIE Proceedings of SPIE (Advanced Optical Storage Technology),4930, pp.343-350 (2002).*
  • Tokinobu Mitasaki, Atsushi Okamoto, Satoshi Honma:“Optical maintenance technique for dynamic hologram and its application for all-optical interconnection”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Digest, 10P-18, pp22・・・
    2002年 [査読無し][通常論文]
     
    Tokinobu Mitasaki, Atsushi Okamoto, Satoshi Honma:“Optical maintenance technique for dynamic hologram and its application for all-optical interconnection”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Digest, 10P-18, pp222-223(2002).*
  • Tohru Hasegawa, Atsushi Okamoto, Takahiko Nakatogawa, Kunihiro Sato:“Performance enhancement for all-optical interconnection with WDM signals in photorefractive crystal”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Diges・・・
    2002年 [査読無し][通常論文]
     
    Tohru Hasegawa, Atsushi Okamoto, Takahiko Nakatogawa, Kunihiro Sato:“Performance enhancement for all-optical interconnection with WDM signals in photorefractive crystal”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Digest, 10P-17, pp220-221(2002).*
  • Toshiya Kaino, Atsushi Okamoto, Satoshi Honma:“Swicthing Property of Fault Tolerant All-Optical Router by Using Two All-optical switch with Photorefractive Two-Wave Mixing”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Di・・・
    2002年 [査読無し][通常論文]
     
    Toshiya Kaino, Atsushi Okamoto, Satoshi Honma:“Swicthing Property of Fault Tolerant All-Optical Router by Using Two All-optical switch with Photorefractive Two-Wave Mixing”, Seventh Optoelectronics and Communications Conference (OECC 2002) Technical Digest, 10A3-7, pp102-103(2002).*
  • 「交差偏光4波混合を用いたホトリフラクティブディスクタイプメモリにおける多重記録特性の解析及び実験」
    電子情報通信学会論文誌 C J84-C (11) 1083 -1089 2001年 [査読無し][通常論文]
  • 「フォトリフラクティブ2波混合と制御光を用いた全光インタコネクション」
    電子情報通信学会論文誌 C J84-C (9) 900 -901 2001年 [査読無し][通常論文]
  • 「光学的インバースフィルタへのフォトリフラクティブ4波混合の適用」
    電子情報通信学会論文誌 C J84-C (No.3) 222 -223 2001年 [査読無し][通常論文]
  • Tokinobu Mitasaki, Atsushi Okamoto, Satoshi Honma: “All-optical interconnection and routing memory by photorefractive full-linear resonator”, 8th Microoptics Conference, MOC’01, H25, pp.226-229(2001-10).*
    2001年 [査読無し][通常論文]
  • Tokinobu Mitasaki, Atsushi Okamoto and Satoshi Honma: “All-optical interconnection with pattern memory function by photorefractive full-linear resonator”, Proceedings of SPIE (ISPA 2001), Vol.4598-33, pp.225-232, (2001-11).*
    2001年 [査読無し][通常論文]
  • Hiroyuki Nihei and Atsushi Okamoto: “All-optical switching scheme using a three-level atomic system within photonic crystals”, Proceedings of SPIE (ISPA 2001), Vol.4598-31, pp.217-224,(2001-11).*
    2001年 [査読無し][通常論文]
  • Noriyasu Tsuji, Atsushi Okamoto, Yoshihisa Takayama and Takahiko Nakatogawa: ”Three-dimensional analysis of code processing in photorefractive holographic memory”, Proceedings of SPIE (ISPA 2001), Vol.4598-34, pp.233-240(2001-11).*
    2001年 [査読無し][通常論文]
  • Mitsuru Toishi, Atsushi Okamoto and Kunihiro Sato: “Experiment on automatic data duplication in all-optical holographic memory”, Proceedings of SPIE (ISPA 2001), Vol.4598-28, pp.200-207(2001-11).*
    2001年 [査読無し][通常論文]
  • Hisatoshi Funakoshi, Atsushi Okamoto and Kunihiro Sato: “Image reading and writing experiment on photorefractive nondestructive memory”, Proceedings of SPIE (ISPA 2001), Vol.4598-27, pp.193-199(2001-11).*
    2001年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto: “Switching Effect of a Single Three-level Atom Within Photonic Crystals for Quantum Computation”, 8th Microoptics Conference, MOC’01, H41, pp.290-293,(2001-10).*
    2001年 [査読無し][通常論文]
  • Noriyasu Tsuji, Atsushi Okamoto, Yoshihisa Takayama, Satoshi Honma: “All-optical Authentication and Unlawful Access Detection by Photorefractive Four-wave Mixing”, 8th Microoptics Conference, MOC’01, H29, pp.242-245(2001-10).*
    2001年 [査読無し][通常論文]
  • Takahiko Nakatogawa, Atsushi Okamoto Kunihiro Sato: “Multi-channel reading in free space for WDM signals with photorefractive connection module”, 8th Microoptics Conference, MOC’01, H26, pp.230-233(2001-10).*
    2001年 [査読無し][通常論文]
  • Satoshi Honma, Atsushi Okamoto, Yoshihisa Takayama, "Photorefractive duplex two-wave mixing and all-optical deflection switch", J. Opt. Soc. Am. B, 18(7), pp. 974-981, (2001-7).*
    2001年 [査読無し][通常論文]
  • Takahiko Nakatogawa, Atsushi Okamoto, Kunihiro Sato: “Multiplicity of free space WDM system with Photorefractive Connection Module”, Conference Proceedings of OEEC/IOOC 2001, Poster Session-Stream 1-1, pp.341-343(2001-07).*
    2001年 [査読無し][通常論文]
  • Satoshi Honma, Atsushi Okamoto: “All-optical interconnection by optical feedback and double phase conjugation”, Conference Digest of CLEO/Europe-EQEC Focus Meetings 2001,C-NLP 230, pp.217(2001-06).*
    2001年 [査読無し][通常論文]
  • Takahiko Nakatogawa, Atsushi Okamoto, Kunihiro Sato: “Experiment on free space WDM system with Photorefractive Connection Module”, Conference Digest of CLEO/Europe-EQEC Focus Meetings 2001,C-NLP 226, pp.213(2001-06).*
    2001年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto: “Photonics crystal systems for high-speed optical memory device on an atomic scale”,ICOSM2001-06,Proceedings of SPIE Vol. 4416, pp.470-473(2001-06).*
    2001年 [査読無し][通常論文]
  • Atsushi Okamoto, Satoshi Honma, Toshiya Kaino, Mitsuru Toishi: “Fault-tolerant system using all-optical sensing and feed back circuits”,ICOSM2001-06,Proceedings of SPIE Vol. 4416, pp.396-399(2001-06).*
    2001年 [査読無し][通常論文]
  • Takayuki Kaneda, Atsushi Okamoto, Kunihiro Sato, “All-optical image cross connector and the picture distribution technology,”Optics in Computing, OSA Technical Digest, OWD2 , pp.96-98 (2001-1).*
    2001年 [査読無し][通常論文]
  • Yoshiyasu Kato, Atsushi Okamoto, Kunihiro Sato, “Multi-valued phase-conjugate reflectivity controlled by rotation of the pump beam polarization,”Optics in Computing, OSA Technical Digest, OWD1 ,pp.93-95(2001-1).*
    2001年 [査読無し][通常論文]
  • Toshiya Kaino, Atsushi Okamoto, Tsutomu Nakada and Takayuki Kaneda:”Fault tolerant all-optical routing device with two-wave mixng”,CLEO/Pacific Rim 2001 TECHNICAL DIGEST Volume-II,pp.256-257(2001-07).*
    2001年 [査読無し][通常論文]
  • Satoshi Honma, Atsushi Okamoto: “Resonant State Switching with Photorefractive Enhanced Semi-Linear Configuration, and It’s Applications”, Conference Proceedings of OEEC/IOOC 2001, Poster Session-Stream 2-6, pp.386-398(2001-07).*
    2001年 [査読無し][通常論文]
  • Atsushi Okamoto, Takahiko Nakatogawa, Tohru Hasegawa, Satoshi Honma: “All-optical Reconfigurable Interconnection for Free Space and Wavelength Division Multiplexing System”, 8th Microoptics Conference, MOC’01, H24, pp.222-225(2001-10).*
    2001年 [査読無し][通常論文]
  • Hisatoshi Funakoshi, Atsushi Okamoto, Yoshihisa Takayama, Kunihiro Sato: “Thresholding Property of Nondestructive Memory with Photorefractive Crystal”, Conference Proceedings of OEEC/IOOC 2001, Poster Session-Stream 2-7, pp.389-391(2001-07).*
    2001年 [査読無し][通常論文]
  • Mitsuru Toishi, Atsushi Okamoto, Satoshi Honma, Masatoshi Bunsen: “Optimization of Beam Intensities For High Efficient Fault-tolerant Holographic Memory”, Conference Proceedings of OEEC/IOOC 2001, Poster Session-Stream 2-9, pp.394-396(2001-07).*
    2001年 [査読無し][通常論文]
  • Hiroyuki Nihei, Atsushi Okamoto: “Proposal of Optical Multifunctional Device Composed of an Atomic System Placed Within Photonic Crystals”, Conference Proceedings of OEEC/IOOC 2001, Poster Session-Stream 2-10, pp.397-398(2001-07).*
    2001年 [査読無し][通常論文]
  • Hisatoshi Funakoshi, Atsushi Okamoto, Masatoshi Bunsen, Kunihiro Sato: “Photorefractive Nondestructive Memory with Optical Feedback Circuit”, Conference Digest of CLEO/Europe-EQEC Focus Meetings 2001,C-NLP 231, pp.218(2001-06).*
    2001年 [査読無し][通常論文]
  • Mitsuru Toishi, Atsushi Okamoto, Satoshi Honma and Masatoshi Bunsen ”Fault-tolerant holographic memory with two photorefractive crystals”,CLEO/Pacific Rim 2001 TECHNICAL DIGEST Volume-II,pp.160-161(2001-07).*
    2001年 [査読無し][通常論文]
  • Toshiya Kaino, Atsushi Okamoto, Yasuhiko Nakanishi, Kunihiro Sato: “Experiment of Fault Tolerant All-Optical Routing Device with two-wave mixing”, Conference Proceedings of OEEC/IOOC 2001, Poster Session-Stream 1-11, pp.363-364(2001-07).*
    2001年 [査読無し][通常論文]
  • Hiroyuki Nihei and Atsushi Okamoto: “Switching Time of Optical Memory Devices Composed of Photonic Crystals with an Impurity Three-Level Atom”, Jpn. J. Appl. Phys., Vol. 40, Part 1(No. 12), pp.6835-6840 (2001-12).*
    2001年 [査読無し][通常論文]
  • Kaneda, T., Okamoto, A., Honma, S., Nakada, T., and Sato, K.: “Optical image connector with photorefractive four-wave mixing”, proceedings of 2nd International Conference on Optical Design and Fabrication (ODF2000), P27: 229-232 (2000)*
    2000年 [査読無し][通常論文]
  • Nomura, J., Okamoto, A., Okada, H., Sato, K.: “Experiment on channel branching in the photorefractive connection module”, proceedings of 2nd International Conference on Optical Design and Fabrication (ODF2000), P28: 233-246 (2000)*
    2000年 [査読無し][通常論文]
  • Nihei, H., Okamoto, A.: “Dynamic Phase Properties of Atomic Population on the Excited State in a Photonic Crystal”, Fifth Optoelectronics and Communications Conference (OECC 2000) Technical Digest, 12P-37: 260-261, (2000) . *
    2000年 [査読無し][通常論文]
  • Okamoto, A.: “All Optical Interconnection by Photorefractive Effect and Self-Routing Application”, Optics in Computing 2000, SPIE 4089: OC2000, 939-947 (2000)*
    2000年 [査読無し][通常論文]
  • Nakada, T., Okamoto, A., Sato, K.: “Experiments of reconfigurable all-optical interconnection by beam fanning switch”, Conference on Lasers and Electro-Optics (CLEO2000), TECHNICAL DIGEST, CLEO2000: 508 (2000) *
    2000年 [査読無し][通常論文]
  • Kaneda, T., Okamoto, A., Sato, K., Nakada, T.: “Experiment on All-Optical Interconnection with Photorefractive Four-Wave Mixing”, Fifth Optoelectronics and Communications Conference (OECC 2000) Technical Digest, 12P-5:196-197, (2000) *
    2000年 [査読無し][通常論文]
  • Kato, Y., Okamoto, A., Takayama, Y.: “Multi-valued property of phase conjugation and control of its threshold condition”, Conference on Lasers and Electro-Optics, TECHNICAL DIGEST, CLEO2000: 159-160 (2000)*
    2000年 [査読無し][通常論文]
  • Nakatogawa, T., Okamoto, A., Kentaro Watanabe, Sato, K., Okada, H.: “Gain Stabilized Configuration in PRCM Circuit and Optical Bus System”, Optics in Computing 2000, SPIE 4089: OC2000, 345-350 (2000) *
    2000年 [査読無し][通常論文]
  • Bunsen, M., Okamoto, A., Sato, K.: “Enhancement of storage density in photorefractive disk-type memory with cross polarized four-wave mixing”, Optics in Computing 2000, SPIE 4089: OC2000, .806-814 (2000) *
    2000年 [査読無し][通常論文]
  • Honma, S., Okamoto, A., Takayama, Y.: “Optical Demodulator with Photorefractive Cross Polarized Duplex Two-Wave Mixing”, Optics in Computing 2000, SPIE 4089: OC2000, 867-875 (2000)
    2000年 [査読無し][通常論文]
  • Yoshida,T., Okamoto, A., Y. Takayama, Sato, K. : “Operable conditions of the beam-fanning novelty filter for the c axis and the incident angle”, App. Opt.,39(32): 5940-5948 (2000)*
    2000年 [査読無し][通常論文]
  • Funakoshi, H., Okamoto, A., Bunsen,M. and Sato, K.: “Nondestructive readout technique with photorefractive holographic memory”, proceedings of 2nd International Conference on Optical Design and Fabrication (ODF2000), P29: 237-240 (2000)*
    2000年 [査読無し][通常論文]
  • Honma, S., Okamoto, A., Sato, K.: “Experiment on All-Optical Switch with Photorefractive Duplex Two-Wave Mixing”, Conference on Lasers and Electro-Optics/Europe (CLEO/Europe2000), CONFERENCE DIGEST, CtuN6: 156,(2000)*
    2000年 [査読無し][通常論文]
  • Takahashi, Y., Okamoto, A., Honma, S.: “All-optical Channel Selector and Angular Resolution of KNbO3 Crystal”, Fifth Optoelectronics and Communications Conference (OECC 2000) Technical Digest, 12P-67: 320-321, ( 2000) .*
    2000年 [査読無し][通常論文]
  • Nakanishi, Y., Okamoto, A., Nakada, T., Honma, S.: “All-optical interconnection by matrix switching with photorefractive two-wave mixing”, Conference on Lasers and Electro-Optics /Europe(CLEO/Europe2000), CONFERENCE DIGEST, CTuK86: 129,(2000)*
    2000年 [査読無し][通常論文]
  • Bunsen, M., Okamoto, A., Sato, K.: “Optimization of multiplexing scheme in photorefractive disk-type memory”, Conference on Lasers and Electro-Optics/Europe(CLEO/Europe2000), CONFERENCE DIGEST, CtuK77: 125,(2000)*
    2000年 [査読無し][通常論文]
  • Tsuji, N., Okamoto, A., Honma, S. and Bunsen, M.: “AUTHENTIC FUNCTION IN PHOTOREFRACTIVE HOLOGRAPHIC MEMORY”, International Symposium on Optical Memory (ISOM2000), Technical Digest, Fr-J-27: 160-161(2000).*
    2000年 [査読無し][通常論文]
  • Nihei, H., Okamoto, A.: “Switching time of optical memory devices composed of photonic crystals”, proceedings of 2nd International Conference on Optical Design and Fabrication (ODF2000), P20: 201-204 (2000)*
    2000年 [査読無し][通常論文]
  • Tsutomu Nakada, Atsushi Okamoto, Yoshihisa Takayama, Kunihiro Sato: “Free-space All-optical Interconnection with a Photorefractive Crystal”, CLEO/Pacific Rim99 TECHNICAL DIGEST, Volume 2, pp.373-374 (1999)*
    1999年 [査読無し][通常論文]
  • Hajime Okada, Atsushi Okamoto, Yoshihisa Takayama, Kunihiro Sato: “Control Method of Bistable Values of Phase Conjugate Reflectivity by Erase Beam in Photorefractive Four-Wave Mixing with Beam Fanning”, Optical Society of America, Trends in Optics and ・・・
    1999年 [査読無し][通常論文]
     
    Hajime Okada, Atsushi Okamoto, Yoshihisa Takayama, Kunihiro Sato: “Control Method of Bistable Values of Phase Conjugate Reflectivity by Erase Beam in Photorefractive Four-Wave Mixing with Beam Fanning”, Optical Society of America, Trends in Optics and Photonics, TOPS Volume XXVII, pp.287-291(1999)
  • ”ホトリフラクティブ4波混合における位相共役反射率の消去光による双安定制御”
    電子情報通信学会論文誌 C-I J82-C-I (8) 477 -483 1999年 [査読無し][通常論文]
  • Atsushi Okamoto, Junichi Nomura, Hisashi Matsuoka, Yoshihisa Takayama, Kunihiro Sato: “Complementary Arrangement of Photorefractive Connection Module for Optical Bus System”, Optical Society of America, Trends in Optics and Photonics, TOPS Volume XXVII・・・
    1999年 [査読無し][通常論文]
     
    Atsushi Okamoto, Junichi Nomura, Hisashi Matsuoka, Yoshihisa Takayama, Kunihiro Sato: “Complementary Arrangement of Photorefractive Connection Module for Optical Bus System”, Optical Society of America, Trends in Optics and Photonics, TOPS Volume XXVII, pp.568-574(1999)
  • Atsushi Okamoto, Yoshihisa Takayama, Hajime Okada: “ OPTICAL CONTROLLED VECTOR MULTIPLIER WITH PHOTOREFRACTIVE FOUR-WAVE MIXING”, Micro optics Conference-99, MF32, pp.236-239(1999)*
    1999年 [査読無し][通常論文]
  • Masatoshi Bunsen, Atsushi Okamoto, Motoyuki Ogawa, Kazunori Ikeda: “CROSS TALK REDUCTION AND NON-DESTRUCTIVE TECHNIQUE WITH PHOTOREFRACTIVE HOLOGRAPHIC MEMORY”, Micro optics Conference-99, MF34, pp.244-247(1999)*
    1999年 [査読無し][通常論文]
  • A. Okamoto, K. Watanabe, H. Matsuoka, Y. Takayama:”PRCM and its optical bus application by photorefractive four-wave mixing with cross-polarization pumping”, Proceedings of SPIE(Optical Engineering for Sensing and Nanotechnology - ICOSN'99), 3740, pp.4・・・
    1999年 [査読無し][通常論文]
     
    A. Okamoto, K. Watanabe, H. Matsuoka, Y. Takayama:”PRCM and its optical bus application by photorefractive four-wave mixing with cross-polarization pumping”, Proceedings of SPIE(Optical Engineering for Sensing and Nanotechnology - ICOSN'99), 3740, pp.450-453 (1999)*
  • A. Okamoto, H. Matsuoka, M. Saito, Y. Takayama, M. Takamura : “Concept of Photorefractive Connection Module by Photorefractive Four-Wave Mixing with Extraordinary Writing Beams and an Ordinary Reading Beam”, Opt. Rev., 6, 3, pp.189-195 (1999)*
    1999年 [査読無し][通常論文]
  • Atsushi Okamoto, Junichi Nomura, Hisashi Matsuoka, Yoshihisa Takayama, Kunihiro Sato: “Photorefractive Connection Module and Multistage Optical Bus System”, CLEO/Pacific Rim99 TECHNICAL DIGEST, Volume 2, pp.371-372 (1999)*
    1999年 [査読無し][通常論文]
  • Satoshi Honma, Atsushi Okamoto, and Yoshihisa Takayama: “All-optical Photorefractive Switch with Phase Difference between Control Beams”, Optical Society of America, Trends in Optics and Photonics, TOPS Volume XXVII, pp.575-580(1999)
    1999年 [査読無し][通常論文]
  • Atsushi Okamoto, Tsutomu Nakada, Satoshi Honma : ”Reconfigurable Optical Interconnection Controlled by Light, with Photorefractive Technique”, PROCEEDINGS APCC/OECC’99, Vol.1, 136, pp.397-400 (1999)*
    1999年 [査読無し][通常論文]
  • Kentaro Watanabe, Atsushi Okamoto, Yoshihisa Takayama : “Gain Stabilization in Optical Bus System with Cascaded PRCM”, PROCEEDINGS APCC/OECC’99, Vol.1, 136, pp.409-412 (1999)*
    1999年 [査読無し][通常論文]
  • Satoshi Honma, Atushi Okamoto, Yoshihisa Takayama, Kunihiro Sato: “Proposition of All-optical Switch with Photorefractive Crystal and Analysis of the Influence of the Phase Mismatching”, CLEO/Pacific Rim99 TECHNICAL DIGEST, Volume 2, pp.573-574 (1999)*
    1999年 [査読無し][通常論文]
  • 2. Takayama, Y., Okamoto, A.,Saito, M. and Sato,K.: "Cross polarized photorefractive four-wave mixing with extraordinary writing beams and an ordinary reading beam", Appl. Opt., 37, 5: 2967-2973 (1998)*
    1998年 [査読無し][通常論文]
  • 1. Takayama,Y.,Okamoto, A.,Sato, Kumagai,K. and Aizawa,Y.: "Study on optimum incident angles of cross polarized four-wave mixing with a photorefractive crystal", Opt. Rev., 5, 1: 49-54 (1998)*
    1998年 [査読無し][通常論文]
  • 3. Matsuoka, H.,Okamoto, A., Sato, K., Takamura,M.: "Reflectivity of cross-polarized four-wave mixing in consideration of pump depletion", J. Opt. Soc. Am. B, 15, 5: 1545-1552 (1998)*
    1998年 [査読無し][通常論文]
  • 4. Takamura, M., Okamoto A. and Sato,K.: "Steady-state analysis of photorefractive ring resonator with self-pumped four-wave mixing (PRRR-SPFWM)", IEICE, Trans. Electron., E81-C, 7: 1122-1127 (1998)*
    1998年 [査読無し][通常論文]
  • 5. Okada, H., Okamoto, A., Takayama,Y.: "Bistability control of phase conjugate reflectivity by erase beam in photorefractive four wave mixing", Third Optoelectronics and Communications Conference (OECC'98) Technical Digest, 14P-33:252-253, Makuhari Me・・・
    1998年 [査読無し][通常論文]
     
    5. Okada, H., Okamoto, A., Takayama,Y.: "Bistability control of phase conjugate reflectivity by erase beam in photorefractive four wave mixing", Third Optoelectronics and Communications Conference (OECC'98) Technical Digest, 14P-33:252-253, Makuhari Messe (1998)*
  • 「Cat型位相共役器による消去光を用いた光インタコネクション」
    『電子情報通信学会論文誌』 C-I J81-C-I (9) 535 -543 1998年 [査読無し][通常論文]
  • Takayama, Y., Okamoto, A., Sato, K. and Takamura, M. : "Bistable phase conjugate reflectivity controlled by forward pump beam", J. Opt. Soc. Am. B., 14(10) : 2664-2669 (1997)*
    1997年 [査読無し][通常論文]
  • Takamura, M., Okamoto, A., Sato, K. and Takayama, Y. : "Unidirectional/Bidirectional Switchable Ring Resonator with Photorefractive Self-Pumped Four-Wave Mixing", Proc. 1997 Topical Meeting on Photorefractive Materials, Effects and Devices (Optical Soc・・・
    1997年 [査読無し][通常論文]
     
    Takamura, M., Okamoto, A., Sato, K. and Takayama, Y. : "Unidirectional/Bidirectional Switchable Ring Resonator with Photorefractive Self-Pumped Four-Wave Mixing", Proc. 1997 Topical Meeting on Photorefractive Materials, Effects and Devices (Optical Society of America, PR'97), FP 25 : 621-624 (1997)*
  • Saito, M., Okamoto, A., Takayama, Y. and Takamura, M. : "Phase matching property of cross polarized four wave mixing in BaTiO3 crystal and optical bus application", Proc. 1997 Topical Meeting on Photorefractive Materials, Effects and Devices (Optical S・・・
    1997年 [査読無し][通常論文]
     
    Saito, M., Okamoto, A., Takayama, Y. and Takamura, M. : "Phase matching property of cross polarized four wave mixing in BaTiO3 crystal and optical bus application", Proc. 1997 Topical Meeting on Photorefractive Materials, Effects and Devices (Optical Society of America. PR'97), WP 28 : 204-207 (1997)*
  • Takayama, Y., Okamoto, A., Sato, K and Saito, M. * : "Method to control the bistability of four-wavemixing with a photorefractive crystal", Proc. 1997 Topical Meeting on Photorefractive Materials, Effects and Devices (Optical Society of America, PR‘97)・・・
    1997年 [査読無し][通常論文]
     
    Takayama, Y., Okamoto, A., Sato, K and Saito, M. * : "Method to control the bistability of four-wavemixing with a photorefractive crystal", Proc. 1997 Topical Meeting on Photorefractive Materials, Effects and Devices (Optical Society of America, PR‘97), WP26 : 196-197 (1997)*
  • Takayama, Y., Okamoto, A. and Sato, K. : "High transient reflectivity of four-wave mixing in a BaTiO3 crystal by pulsed pump beam", J. Opt. Soc. Am. B., 14(10) : 2570-2576 (1997)*
    1997年 [査読無し][通常論文]
  • Saito, M., Okamoto, A., Sato, K. and Takayama, Y. : "Phase matching property of cross polarization four wave mixing in BaTiO3crystal.", Opt. Rev., 4(6) : 686-690 (1997)*
    1997年 [査読無し][通常論文]
  • 「ホトリフラクティブ結晶とパルス光を用いた4光波混合における回折効率の計算と実験」
    『電子情報通信学会論文誌』 C-I, J80-C-1(1)/,18-24 1997年 [査読無し][通常論文]
  • 「ホトリフラクティブ結晶を用いた4波混合における双安定性の前進ポンプ光による制御」
    『電子情報通信学会論文誌』 c-I, J80-c-I(11)/,510-516 1997年 [査読無し][通常論文]
  • 「自己励起形4波混合における位相共役反射率の特性」
    『電子情報通信学会論文誌C-I』 J79-C-I (4) 109 -116 1996年 [査読無し][通常論文]
  • Y. Takayama, A. Okamoto and K. Sato : "High-efficiency transient phase conjugation by turning on reading beam incident upon steady-state transmission grating in BaTiO3 crystal", Optics Communications, 123 : 603-606 (1996)*
    1996年 [査読無し][通常論文]
  • 「ガウスビームポンピングを用いた前進4波混合における位相共役光強度の光線角度に対する特性」
    『電子情報通信学会論文誌C-I』 J79-C-I (8) 295 -302 1996年 [査読無し][通常論文]

特許

  • 特許4997428:ホログラム記録・消去装置およびホログラム記録・消去方法  
    文仙正俊, 古田洋介, 岡本 淳
  • 光波長フィルタ装置
    特許公開2009-145429
  • ホログラム複製装置およびホログラム複製方法
    特許公開2008-287107
  • 記録再生装置、記録再生方法、再生装置及び再生方法
    特開2008-97738
  • 記録再生装置、記録再生方法、再生装置及び再生方法
    特許公開2008-97738
  • 特許4815595:多重ホログラム転写装置および多重ホログラム転写方法  
    伊藤輝将, 岡本 淳
  • ファニング光結合構造およびそのファニング光結合構造を用いた光増幅器
    特開2007-43087
  • 双方向光配線形成方法
    特開2007-41519
  • 特許4876222:画像記録方法  
    岡本 淳, 森竹 潔
  • 特許4765067:ホログラムメモリ装置およびこの装置に適用されるホログラムリフレッシュ方法  
    岡本 淳, 伊藤 輝将
  • 特許4670047:光中継装置および光中継方法  
    岡本 淳, 村中 秀史
  • 特開2005-189844:光インターコネクション装置および光インターコネクション方法  
    岡本 淳, 本藤 聡一郎, 高木 清史
  • 位相共役光発生装置
    特開2005-292792
  • ホログラム処理装置およびホログラム処理方法
    特開2006-208858
  • ホログラム記録装置およびホログラム記録方法
    特開2006-184570
  • 特許4533770:光インターコネクション装置および光インターコネクション方法  
    岡本 淳, 植村 俊介, 高木 清史
  • ホログラムメモリ装置およびホログラム記録方法
    特開2005-189845
  • ホログラムメモリ装置及びホログラムの消去方法
    特開2006-126642
  • ホログラム多重記録装置およびホログラム多重記録方法ならびにホログラム再生方法
    特開2005-134659
  • 特許3811777:光スイッチ装置および光伝搬経路接続切り替え装置  
    高山 佳久, 岡本 淳, 本間 聡  
    特許第3811777
  • 光伝送システムおよび光伝送方法
    特開2004-165966
  • 特許4060134:マトリクススイッチ型インターコネクション装置およびそのインターコネクション方法  
    岡本 淳, 高木 清史
  • 特許4285941:ホログラフィック光メモリ装置およびそのメモリ修復方法  
    岡本 淳, 本間 聡, 甲斐野 俊也, 外石 満, 高木 清史
  • ホトリフラクティブ導波路型インターコネクション装置およびそのインターコネクション方法
    特開2003-255418
  • 特願2013-233492:複素振幅像生成装置および複素振幅像生成方法  
    岡本 淳, 渋川敦史
  • 特願2013-168989:複素振幅画像再生装置および複素振幅画像再生方法、ならびに、散乱位相画像生成装置および散乱位相画像生成方法  
    岡本 淳, 渋川敦史, 後藤優太
  • 特願2012-213102:ノイズ除去方法およびノイズ除去装置,記録再生方法および記録再生装置,ならびに,画像計測方法および画像計測装置  
    岡本 淳, 渋川敦史, 若山雄太
  • 岡本 淳, 森田一行

受賞

  • 2012年11月 Outstanding Student Paper Award, IWH2012
     Interpage crosstalk suppression by spatial spectrum diffusion and digital phase conjugate reconstruction 
    受賞者: Atsushi Shibukawa;Atsushi Okamoto;Yuta Wakayama;Akihisa Tomita;Hisatoshi Funakoshi;Kunihiro Sato
  • 2012年10月 ISOM2012 Best Student Paper Award
     38-Level Spatial Quadrature-Amplitude Modulation Recording with Double-Referential Holography 
    受賞者: Keisuke Zukeran;Atsushi Okamoto;Masanori Takabayashi;Atsushi Shibukawa;Akihisa Tomita
  • 2006年 ISOM Excessent Student Award
  • 2005年 Best Paper Award
  • 2005年 Best Paper Award
  • 2001年 General Research Award
     
    受賞者: 岡本 淳

共同研究・競争的資金等の研究課題

  • 光複素振幅制御技術を用いたモード拡散多重光ファイバ通信に関する研究
    科学研究費補助金
    研究期間 : 2013年 
    代表者 : 岡本 淳
  • 光ファイバMIMO通信技術創出に向けての多重空間モード分離・結合デバイスの研究
    科学研究費補助金:
    研究期間 : 2009年 -2011年 
    代表者 : 岡本 淳
  • 光集積回路・導波路チップ間のリコンフュギュラブルな自動配線技術
    テレコム先端技術研究支援センター:平成20年度SCAT研究助成(研究費助成)
    研究期間 : 2008年 -2010年 
    代表者 : 岡本 淳
  • ダイナミック・リコンフィギュラブルな光素子の創出
    三菱財団:[e11] 第39回三菱財団研究助成 自然科学研究助成
    研究期間 : 2008年 -2009年 
    代表者 : 岡本 淳
  • しきい値秘密分散機能を有する全光学的な暗号・認証技術に関する研究
    科学研究費補助金
    研究期間 : 2008年 -2009年 
    代表者 : 岡本 淳

教育活動情報

主要な担当授業

  • 光エレクトロニクス特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学院
    キーワード : 半導体レーザ、光検出、光通信、量子通信、非線形光学、高調波発生、パラメリック発振、光誘起屈折率効果
  • 光デバイス学特論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 情報科学研究科
    キーワード : 半導体レーザ、光検出、光通信、量子通信、非線形光学、高調波発生、パラメリック発振、光誘起屈折率効果
  • 光エレクトロニクス特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学院
    キーワード : 半導体レーザ、光検出、光通信、量子通信、非線形光学、高調波発生、パラメリック発振、光誘起屈折率効果
  • 光デバイス学特論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 情報科学研究科
    キーワード : 半導体レーザ、光検出、光通信、量子通信、非線形光学、高調波発生、パラメリック発振、光誘起屈折率効果
  • 一般教育演習(フレッシュマンセミナー)
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 光、レーザ、LED、光通信、光ファイバ、光ディスクメモリ、デジタルカメラ、ホログラム、3次元ディスプレイ、光計測・イメージング
  • 光システム
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : レーザー、発光ダイオード、光増幅器、光検出器、光変調器、光システムの雑音、撮像と表示、光通信システム、光情報処理
  • 応用光工学
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : レーザー、発光ダイオード、光増幅器、光検出器、光変調器、光システムの雑音、撮像と表示、光通信システム、光情報処理

大学運営

委員歴

  • 2008年 - 2009年   電子情報通信学会   北海道支部 学生会顧問   電子情報通信学会
  • 2009年   電子情報通信学会   本部評議員   電子情報通信学会
  • 2008年   電子情報通信学会   支部評議員   電子情報通信学会
  • 2005年 - 2006年   日本光学会   幹事   日本光学会


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