Dr. Kazuhiko Wakamori Profile

Dr. Kazuhiko Wakamori

at Hamamatsu Photonics KK

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Author

Publications (9)

SPIE Journal Paper | 1 October 2011

Transmission analysis of M-ary phase shift keying multiple-subcarrier modulation signals over radio-on-free-space optical channel with aperture averaging

Chedlia Ben Naila, Kazuhiko Wakamori, Mitsuji Matsumoto

OE, Vol. 50, Issue 10, 105006, (October 2011) https://doi.org/10.1117/12.10.1117/1.3641864

KEYWORDS: Modulation, Phase shift keying, Receivers, Turbulence, Free space optics, Atmospheric turbulence, Scintillation, Transmitters, Optical engineering, Channel projecting optics

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Proceedings Article | 24 August 2010 Paper

Evaluating M-ary PSK multiple-subcarrier modulation over FSO links using aperture averaging

C. Ben Naila, A. Bekkali, K. Kazaura, K. Wakamori, M. Matsumoto

Proceedings Volume 7814, 78140V (2010) https://doi.org/10.1117/12.863105

KEYWORDS: Free space optics, Modulation, Phase shift keying, Receivers, Turbulence, Picosecond phenomena, Free space optical communications, Current controlled current source, Systems modeling, Intermodulation

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Proceedings Article | 24 February 2009 Paper

Experimental evaluation of a radio-on-FSO communication system for multiple RF signal transmission

Kamugisha Kazaura, Pham Dat, Abdelmoula Bekkali, Alam Shah, Toshiji Suzuki, Kazuhiko Wakamori, Mitsuji Matsumoto, Takuya Nakamura, Koichi Takahashi, Takeshi Higashino, Yuji Aburakawa, Katsutoshi Tsukamoto, Shozo Komaki

Proceedings Volume 7199, 719907 (2009) https://doi.org/10.1117/12.808791

KEYWORDS: Free space optics, Antennas, Dense wavelength division multiplexing, Radio over Fiber, Modulation, Atmospheric optics, Radio optics, Televisions, Optical amplifiers, Single mode fibers

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Proceedings Article | 26 January 2009 Paper

Research and development of a next-generation free-space optical communication system

Kazuhiko Wakamori, Kamugisha Kazaura, Mitsuji Matsumoto

Proceedings Volume 7234, 723404 (2009) https://doi.org/10.1117/12.808622

KEYWORDS: Free space optics, Single mode fibers, Telecommunications, Optical fibers, Radio over Fiber, Antennas, Dense wavelength division multiplexing, Optical amplifiers, Optical antennas, Optical tracking

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Achieving an all-optical connection between any wireless communication systems with optical fiber network is one of the ultimate goals of communication network design. An all-optical system providing seamless connection between freespace and optical fiber links by using free-space optical (FSO) communication technology suitable for next generation network has been developed. In order to realize this next-generation FSO communication system in which the transmitted light signal does not undergo any conversion thus achieving all-optical connection, it is necessary to develop a technology for tracking and focusing the free-space optical signal to a single mode fiber (SMF). The developed FSO system incorporates a fine pointing mirror (FPM) for high speed beam control and steering. This novel tracking method can suppress the beam intensity variations as a result of angle-of-arrival fluctuation (AOA) caused by atmospheric turbulence. This paper presents experimental results of a next-generation FSO system providing stable and reliable single channel transmission at 10 Gbps data rates as well as multiple channels using dense wavelength division multiplexing (DWDM). This kind of data rate is not possible to achieve using conventional FSO systems. The developed system can provide transmission capacity equivalent to optical fiber and from its design concept and configuration it is bit-rate and protocol transparent. Furthermore, we present research on Radio-on-FSO (RoFSO) system which is a combination of the developed nextgeneration FSO system and Radio over Fiber (RoF) technology. We demonstrate the possibility of utilizing this system for optical and radio frequency signals transmission. RoFSO technology is independent of the difference in the underlying physical layers for radio system or fiber system, but realizing fusion at the service level. The RoFSO technology is available to realize a universal platform for transparent forwarding various wireless services in a ubiquitous network environment.

Proceedings Article | 26 January 2009 Paper

RoFSO channel modeling considering time-correlation of scintillation and its application to performance evaluation of WLAN signal transmission

Kyung-Hwan Kim, Hideaki Onodera, Takeshi Higashino, Takuya Nakamura, Yuji Aburakawa, Katsutoshi Tsukamoto, Shozo Komaki, Kazuhiko Wakamori, Toshiji Suzuki, Kamugisha Kazaura, Mohamad Shah Alam, Koichi Takahashi, Kazunori Ohmae, Takurou Satou, Mitsuji Matsumoto

Proceedings Volume 7234, 72340L (2009) https://doi.org/10.1117/12.808849

KEYWORDS: Scintillation, Free space optics, Statistical analysis, Channel projecting optics, Atmospheric optics, Atmospheric modeling, Performance modeling, Radio optics, Data modeling, Telecommunications

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Proceedings Article | 13 February 2008 Paper

Design and evaluation of optical antenna module suitable for radio-on free-space optics link system for ubiquitous wireless

Koichi Takahashi, Takeshi Higashino, Takuya Nakamura, Yuji Aburakawa, Katsutoshi Tsukamoto, Shozo Komaki, Kazuhiko Wakamori, Toshiji Suzuki, Kamugisha Kazaura, Alam Mohammad Shah, Kazunori Omae, Mitsuji Matsumoto, Yuichi Miyamoto

Proceedings Volume 6877, 68770H (2008) https://doi.org/10.1117/12.765028

KEYWORDS: Free space optics, Optical antennas, Telecommunications, Radio over Fiber, Optical tracking, Mirrors, Single mode fibers, Sensors, Atmospheric propagation, Atmospheric optics

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Proceedings Article | 13 February 2008 Paper

Characterization of RF signal transmission using FSO links considering atmospheric effects

Alam Mohammad Shah, Pham Tien Dat, Kamugisha Kazaura, Kazuhiko Wakamori, Toshiji Suzuki, Kazunori Omae, Mitsuji Matsumoto, Yuji Aburakawa, Koichi Takahashi, Takuya Nakamura, Takeshi Higashino, Katsutoshi Tsukamoto, Shozo Komaki

Proceedings Volume 6877, 68770D (2008) https://doi.org/10.1117/12.762830

KEYWORDS: Free space optics, Antennas, Dense wavelength division multiplexing, Telecommunications, Atmospheric turbulence, Signal attenuation, Atmospheric modeling, Optical fibers, Visibility, Atmospheric optics

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Proceedings Article | 2 October 2006 Paper

Experimental demonstration of next-generation FSO communication system

Kamugisha Kazaura, Kazunori Omae, Toshiji Suzuki, Mitsuji Matsumoto, Edward Mutafungwa, Koichi Asatani, Tadaaki Murakami, Koichi Takahashi, Hideki Matsumoto, Kazuhiko Wakamori, Yoshinori Arimoto

Proceedings Volume 6390, 63900G (2006) https://doi.org/10.1117/12.685884

KEYWORDS: Free space optics, Telecommunications, Antennas, Mirrors, Sensors, Single mode fibers, Data communications, Atmospheric optics, Optical antennas, Scintillation

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Proceedings Article | 1 March 2006 Paper

Mitigation of atmospheric effects on terrestrial FSO communication systems by using high-speed beam tracking antenna

Kamugisha Kazaura, Kazunori Omae, Toshiji Suzuki, Mitsuji Matsumoto, Takuro Sato, Koichi Asatani, Mitsutoshi Hatori, Tadaaki Murakami, Koichi Takahashi, Hideki Matsumoto, Kazuhiko Wakamori, Yoshinori Arimoto

Proceedings Volume 6105, 61050N (2006) https://doi.org/10.1117/12.655780

KEYWORDS: Free space optics, Scintillation, Antennas, Atmospheric optics, Atmospheric propagation, Telecommunications, Single mode fibers, Atmospheric turbulence, Signal attenuation, Beam propagation method

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Showing 5 of 9 publications

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