K
K. Shimizu
Researcher at Nippon Telegraph and Telephone
Publications - 23
Citations - 1676
K. Shimizu is an academic researcher from Nippon Telegraph and Telephone. The author has contributed to research in topics: Optical fiber & Medicine. The author has an hindex of 9, co-authored 18 publications receiving 1591 citations.
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Journal ArticleDOI
Development of a distributed sensing technique using Brillouin scattering
TL;DR: In this article, a distributed strain and temperature sensing technique that uses Brillouin scattering in single-mode optical fibers is presented, which is based on strain- and temperature-induced changes in the frequency shift.
Journal ArticleDOI
Field test of quantum key distribution in the Tokyo QKD Network
Masahide Sasaki,M. Fujiwara,H. Ishizuka,Werner Klaus,Kentaro Wakui,Masahiro Takeoka,Akihiro Tanaka,K. Yoshino,Y. Nambu,Seigo Takahashi,Akio Tajima,Akihisa Tomita,T. Domeki,Tomonobu Hasegawa,Y. Sakai,H. Kobayashi,T. Asai,K. Shimizu,T. Tokura,Toyohiro Tsurumaru,Mitsuru Matsui,Toshimori Honjo,Kiyoshi Tamaki,Hiroki Takesue,Yasuhiro Tokura,James F. Dynes,Alex Dixon,Andrew W. Sharpe,Zhiliang Yuan,Andrew J. Shields,S. Uchikoga,Matthieu Legre,S. Robyr,Patrick Trinkler,L. Monat,J.-B. Page,G. Ribordy,Andreas Poppe,A. Allacher,O. Maurhart,Thomas Länger,Momtchil Peev,Anton Zeilinger +42 more
TL;DR: In this paper, a novel secure communication network with quantum key distribution in a metropolitan area is reported, where different QKD schemes are integrated to demonstrate secure TV conferencing over a distance of 45km, stable long-term operation and application to secure mobile phones.
Journal ArticleDOI
Coherent self-heterodyne Brillouin OTDR for measurement of Brillouin frequency shift distribution in optical fibers
TL;DR: In this article, a coherent self-heterodyne detection system employing a recently proposed frequency translator, a DFB laser diode, and erbium-doped fiber amplifiers is demonstrated.
Journal ArticleDOI
Characteristics and reduction of coherent fading noise in Rayleigh backscattering measurement for optical fibers and components
TL;DR: In this paper, the effects of frequency shift averaging on fading noise reduction are clarified theoretically, and the relationships between measurement accuracy and other parameters, such as spatial resolution and frequency variation range, are derived.
Journal ArticleDOI
Performance of Long-Distance Quantum Key Distribution Over 90-km Optical Links Installed in a Field Environment of Tokyo Metropolitan Area
K. Shimizu,Toshimori Honjo,Mikio Fujiwara,Toshiyuki Ito,Kiyoshi Tamaki,Shigehito Miki,Taro Yamashita,Hirotaka Terai,Zhen Wang,Masahide Sasaki +9 more
TL;DR: In this article, experimental results for a long-term field trial of 1-GHz clock differential phase shift quantum key distribution that was incorporated in the test-bed optical fiber network installed in the Tokyo metropolitan area were reported.