Prof. Akihisa Tomita Profile

Prof. Akihisa Tomita

Principal Researcher at Hokkaido Univ

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Author

Publications (28)

Proceedings Article | 20 September 2023 Paper

Single-shot complex amplitude measurement technique in rhombic Fourier region using tilted reference light

Nobuhiro Yamagishi, Atsushi Okamoto, Akihisa Tomita

Proceedings Volume 12608, 1260808 (2023) https://doi.org/10.1117/12.3006574

KEYWORDS: Complex amplitude, Image sensors, Image restoration, Fringe analysis, Signal processing, Numerical analysis, Linear filtering, Digital holography, Optical components, Image processing

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Proceedings Article | 17 February 2020 Presentation + Paper

Three-dimensional tomographic imaging and quantitative phase measurement using virtual phase conjugation

Satoshi Kawashima, Atsushi Okamoto, Tomohiro Maeda, Kazuhisa Ogawa, Akihisa Tomita, Ryusuke Osaki, Naoki Hayashi

Proceedings Volume 11245, 1124510 (2020) https://doi.org/10.1117/12.2545353

KEYWORDS: Tomography, Phase conjugation, Phase measurement, 3D image processing, Distortion, Wavefronts, Computer programming

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Proceedings Article | 31 January 2020 Presentation + Paper

Mode-selective switch for ROADM using volume holograms and spatial light modulator

Hotaka Hayashi, Atsushi Okamoto, Tomohiro Maeda, Taijun Shiba, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Yuta Goto, Naoya Wada

Proceedings Volume 11309, 1130908 (2020) https://doi.org/10.1117/12.2544685

KEYWORDS: Switches, Holograms, Volume holography, Spatial light modulators, Signal to noise ratio, Multiplexing, Switching, Diffraction, Multiplexers, Single mode fibers

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Proceedings Article | 31 January 2020 Presentation + Paper

Spatial mode exchange technique using volume holograms with a random optical diffuser to reduce modal cross-talks

Shuanglu Zhang, Atsushi Okamoto, Taijun Shiba, Hotaka Hayashi, Kazuhisa Ogawa, Akihisa Tomita, Taketoshi Takahata, Satoshi Shinada, Yuta Goto, Naoya Wada

Proceedings Volume 11309, 1130909 (2020) https://doi.org/10.1117/12.2545600

KEYWORDS: Holograms, Volume holography, Diffusers, Multiplexing, Optical communications, Modulation, Digital micromirror devices, Holography, Numerical simulations, Telecommunications

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Proceedings Article | 31 January 2020 Presentation + Paper

Collective measurement of DMD in 6-mode 19-core fiber using low-coherence digital holography

Yuta Abe, Atsushi Okamoto, Kazuhisa Ogawa, Akihisa Tomita, Daiki Soma, Yuta Wakayama, Takehiro Tsuritani

Proceedings Volume 11309, 1130904 (2020) https://doi.org/10.1117/12.2545360

KEYWORDS: Single mode fibers, Digital holography, Fourier transforms, Space division multiplexing, Fiber optic communications

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Proceedings Article | 29 January 2018 Presentation + Paper

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

Proceedings Volume 10561, 105610D (2018) https://doi.org/10.1117/12.2288096

KEYWORDS: Digital micromirror devices, Digital holography, Single mode fibers, Spatial filters, Cameras, Beam splitters, Multiplexing, Lenses, Light sources, Fourier transforms

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Proceedings Article | 29 January 2018 Presentation + Paper

Selective spatial mode attenuator using phase-intensity-phase modulation toward mode-division multiplexing transmission

Zihan Zhou, Atsushi Okamoto, Shimpei Shimizu, Akihisa Tomita, Kazuhisa Ogawa, Yuta Wakayama, Takehiro Tsuritani

Proceedings Volume 10561, 105610H (2018) https://doi.org/10.1117/12.2288125

KEYWORDS: Modulation, Phase shift keying, Signal attenuation, Multiplexing, Attenuators, Optical amplifiers, Numerical simulations, Channel projecting optics, Optical fibers

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Proceedings Article | 7 March 2016 Paper

Virtual interferogram-generation algorithm for phase measurement using two interferograms

Jin Nozawa, Atsushi Okamoto, Masataka Toda, Yasuyuki Kuno, Akihisa Tomita

Proceedings Volume 9771, 97710B (2016) https://doi.org/10.1117/12.2212015

KEYWORDS: Spatial light modulators, Charge-coupled devices, Interferometry, Polarization, Beam splitters, Spatial resolution

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Proceedings Article | 13 February 2016 Paper

Highly accurate spatial mode generation using spatial cross modulation method for mode division multiplexing

Hiroki Sakuma, Atsushi Okamoto, Atsushi Shibukawa, Yuta Goto, Akihisa Tomita

Proceedings Volume 9774, 97740K (2016) https://doi.org/10.1117/12.2211948

KEYWORDS: Modulation, Multiplexing, Diffusers, Wavefronts, Spatial light modulators, Fiber optic communications, Multimode fibers, Computer generated holography, Holograms, Diffraction, Diffusion, Numerical simulations

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Proceedings Article | 13 February 2016 Paper

Spatial-mode conversion using random diffuser and spatial light modulator for reduction of modal crosstalk

Koki Ishii, Atsushi Okamoto, Takehiro Tsuritani, Yuta Wakayama, Yuta Goto, Akihisa Tomita

Proceedings Volume 9774, 97740I (2016) https://doi.org/10.1117/12.2212700

KEYWORDS: Diffusers, Multiplexing, Multimode fibers, Spatial light modulators, Fiber optic communications, Phase shift keying, Computer simulations, Modulation, Wavelength division multiplexing networks, Switching, Single mode fibers

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Proceedings Article | 10 March 2015 Paper

Experiment on three-dimensional display using spatial cross modulation method

Yuta Kan, Atsushi Okamoto, Akihisa Tomita, Atsushi Shibukawa, Hisatoshi Funakoshi

Proceedings Volume 9386, 93860Y (2015) https://doi.org/10.1117/12.2180025

KEYWORDS: Particle filters, Diffusers, 3D displays, Computer generated holography, Spatial light modulators, 3D image processing, Modulation, Computer programming, Speckle, Phase shift keying

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Proceedings Article | 5 March 2015 Paper

Optical tomography using a random diffuser and digital phase conjugation

Yuta Goto, Atsushi Okamoto, Atsushi Shibukawa, Akihisa Tomita, Kunihiro Sato

Proceedings Volume 9319, 93191L (2015) https://doi.org/10.1117/12.2078765

KEYWORDS: Objectives, Diffusers, Tomography, Signal processing, Optical coherence tomography, Spatial filters, Interference (communication), Phase conjugation, Spatial resolution, Tissues

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Proceedings Article | 7 February 2015 Paper

Parallel and simultaneous spatial mode conversion using photorefractive crystal for photonic cross-connect

Yanfeng Zhao, Atsushi Okamoto, Tomohiro Maeda, Yuki Hirasaki, Akihisa Tomita, Masatoshi Bunsen

Proceedings Volume 9389, 93890H (2015) https://doi.org/10.1117/12.2078767

KEYWORDS: Holograms, Signal processing, Crystals, Multiplexing, Spatial light modulators, Polarization, Photonic crystals, Phase shift keying, Holography, Ions

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Proceedings Article | 2 May 2014 Paper

Progressive phase conjugation and its application in reconfigurable spatial-mode extraction and conversion

Atsushi Okamoto, Tomohiro Maeda, Yuki Hirasaki, Akihisa Tomita, Kunihiro Sato

Proceedings Volume 9130, 913012 (2014) https://doi.org/10.1117/12.2051729

KEYWORDS: Phase conjugation, Spatial light modulators, Phase shift keying, Signal detection, Optical fibers, Beam splitters, Charge-coupled devices, Diffusion, Sensors, Imaging systems

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Proceedings Article | 19 February 2014 Paper

High-speed bridge circuit for InGaAs avalanche photodiode single-photon detector

Hirofumi Hashimoto, Akihisa Tomita, Atsushi Okamoto

Proceedings Volume 8997, 899709 (2014) https://doi.org/10.1117/12.2038802

KEYWORDS: Avalanche photodetectors, Single photon detectors, Photodetectors, Quantum efficiency, Bridges, Quantum key distribution, Signal detection, Single photon, Avalanche photodiodes, Indium gallium arsenide

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Proceedings Article | 19 February 2014 Paper

Evaluation of the phase correlation between the optical pulses for transmission in quantum key distribution

Toshiya Kobayashi, Akihisa Tomita, Atsushi Okamoto

Proceedings Volume 8997, 899707 (2014) https://doi.org/10.1117/12.2037594

KEYWORDS: Quantum key distribution, Visibility, Light sources, Polarization, Clocks, Interferometers, Modulators, Semiconductor lasers, Modulation, Information security

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Proceedings Article | 5 February 2013 Paper

Separation of LP modes using volume holographic demultiplexer with a dual-wavelength method for mode division multiplexing

Kento Kawabata, Atsushi Okamoto, Satoshi Honma, Yuta Wakayama, Kunihiro Sato, Akihisa Tomita

Proceedings Volume 8647, 86470C (2013) https://doi.org/10.1117/12.2003459

KEYWORDS: Demultiplexers, Multiplexing, Holography, Signal processing, Volume holography, Holograms, Signal detection, Diffraction, Spatial light modulators, Modulation

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Proceedings Article | 19 May 2012 Paper

Novel photon detection technologies for quantum communications

M. Sasaki, A. Tanaka, M. Fujiwara, K. Yoshino, S. Takahashi, Y. Nambu, A. Tomita, A. Tajima, S. Miki, T. Yamashita, H. Terai, Z. Wang, K. Tsujino, D. Fukuda, M. Takeoka

Proceedings Volume 8375, 837503 (2012) https://doi.org/10.1117/12.919917

KEYWORDS: Photodetectors, Avalanche photodetectors, Quantum key distribution, Receivers, Signal detection, Sensors, Quantum communications, Indium gallium arsenide, Superconductors, Nanowires

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Proceedings Article | 18 May 2011 Paper

Autonomous and dynamic reconfigurable waveguide for optical interconnection with large shift-tolerance

Atsushi Okamoto, Kazutaka Hira, Alexander Grabar, Hisatoshi Funakoshi, Yuta Wakayama, Akihisa Tomita

Proceedings Volume 7944, 79440G (2011) https://doi.org/10.1117/12.874389

KEYWORDS: Waveguides, Diffraction, Crystals, Optical components, Laser crystals, Optical interconnects, Modulation, Switching, Photorefraction, Tolerancing

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Proceedings Article | 22 February 2011 Paper

Optical inter-satellite communication with dynamically reconfigurable optical device using Sn[sub]2[/sub]P[sub]2[/sub]S[sub]6[/sub] crystal

Kaori Nishimaki, Atsushi Okamoto, Tomohiro Fujita, Alexander Grabar, Masanori Takabayashi, Jun Uozumi, Akihisa Tomita, Yoshihisa Takayama

Proceedings Volume 7923, 79230N (2011) https://doi.org/10.1117/12.874428

KEYWORDS: Crystals, Phase conjugation, Reflectivity, Satellites, Telecommunications, Laser crystals, Satellite communications, Diffraction gratings, Optical communications, Receivers

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Proceedings Article | 24 January 2011 Paper

Ultra-wide tuning range of reconfigurable optical add-drop multiplexer using photorefractive polymer

Yuta Wakayama, Atsushi Okamoto, Akihisa Tomita, Kunihiro Sato

Proceedings Volume 7958, 79580H (2011) https://doi.org/10.1117/12.874434

KEYWORDS: Diffraction gratings, Diffraction, Apodization, Polymers, Multiplexers, Photorefractive polymers, Wavelength division multiplexing, Holograms, Holography, Modulation

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Proceedings Article | 24 January 2011 Paper

All-optical demultiplexer based on dynamic multiple holograms for optical MIMO processing and mode division multiplexing

Takuya Oda, Atsushi Okamoto, Daiki Soma, Akihisa Tomita, Yuta Wakayama

Proceedings Volume 7958, 79580J (2011) https://doi.org/10.1117/12.874427

KEYWORDS: Signal to noise ratio, Holograms, Multiplexing, Demultiplexers, Spatial light modulators, Waveguides, Volume holography, Modulation, Holography, Signal detection

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Proceedings Article | 26 January 2009 Paper

Test and measurement on quantum key distribution systems

Akihisa Tomita

Proceedings Volume 7236, 72360K (2009) https://doi.org/10.1117/12.809879

KEYWORDS: Quantum key distribution, Calibration, Photodetectors, Information security, Modulators, Quantum communications, Sensors, Quantum information, Receivers, Telecommunications

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Proceedings Article | 10 September 2007 Paper

Quantum key distribution system for metropolitan-area networks

A. Tomita

Proceedings Volume 6780, 678012 (2007) https://doi.org/10.1117/12.735100

KEYWORDS: Photons, Quantum key distribution, Clocks, Information security, Error analysis, Optical fibers, Photonic integrated circuits, Interferometers, Modulators, Control systems

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Proceedings Article | 1 June 2005 Paper

1024-Qubits-Quantum Fourier Transform on a Fiber-optics circuit

Akihisa Tomita, Kazuo Nakamura

Proceedings Volume 5833, (2005) https://doi.org/10.1117/12.620516

KEYWORDS: Quantum communications, Polarization, Photons, Phase modulation, Quantum computing, Information operations, Fourier transforms, Fiber optics, Quantum circuits, Error analysis

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Proceedings Article | 11 January 2005 Paper

Recent development of technologies for quantum communication

Akihisa Tomita

Proceedings Volume 5631, (2005) https://doi.org/10.1117/12.577767

KEYWORDS: Quantum key distribution, Avalanche photodetectors, Polarization, Quantum communications, Photodetectors, Interferometers, Single photon, Fermium, Frequency modulation, Sensors

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Proceedings Article | 13 September 2002 Paper

Experimental investigation of pulsed entangled photons and photonic quantum channels

Yoshihiro Nambu, Koji Usami, Akihisa Tomita, Satoshi Ishizaka, Tohya Hiroshima, Yoshiyuki Tsuda, Keiji Matsumoto, Kazuo Nakamura

Proceedings Volume 4917, (2002) https://doi.org/10.1117/12.483034

KEYWORDS: Photons, Quantum information, Quantum communications, Polarization, Tomography, Crystals, Sensors, Quantum computing, Visibility, Quantum cryptography

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Proceedings Article | 6 August 1999 Paper

Space charge and many-body effects on the optical gain in semiconductor quantum wells for advanced laser design

Akihisa Tomita

Proceedings Volume 3625, (1999) https://doi.org/10.1117/12.356864

KEYWORDS: Quantum wells, Electrons, Semiconductors, Semiconductor lasers, Phonons, Scattering, Photons, Laser development, Optical semiconductors, Nonlinear optics

Showing 5 of 28 publications

Conference Committee Involvement (2)

Quantum Communications Realized II

28 January 2009 | San Jose, California, United States

Quantum Communications Realized

10 September 2007 | Boston, MA, United States

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