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Publication
Featured researches published by Mamoru Hirayama.
Japanese Journal of Applied Physics | 1998
Yoshiaki Takeuchi; Mamoru Hirayama; Shin Sumida; Osamu Kobayashi
Properties of a microheater have been greatly improved for use in fused-tapered fiber coupler fabrication by employing a ceramic heat source. Lanthanum chromite was adopted as a heat source because it has the highest melting point for the use in air and can be used without cooling equipment. The usual susceptibility to heat shock exhibited by ceramic heaters was essentially overcome by miniaturizing the structure so that it could handle quick temperature changes during fiber coupler fabrication. The microheater was typically only 22 mm long which helps shorten the fiber coupler length. The lifetime of the microheater was about 1500 h at 1530°C. This is more than 100 times that of the previously developed precious metal microheater. There was only a slight change in the temperature distribution along the heater with heating time. 1.31/1.55-µm wavelength-division-multiplexing (WDM) couplers were fabricated during the lifetime test and it was confirmed that the coupling properties could be very well controlled even after the test.
IEICE Transactions on Electronics | 2005
Yoshiteru Abe; Masaru Kobayashi; Mamoru Hirayama; Ryo Nagase
The increasing number of channels in dense wavelength division multiplexing (DWDM) systems has led to the need for wiring involving a large number of optical fibers in the system racks. We have developed a novel scalable optical fiber wiring system designed to realize as many as 10,000-fiber shuffled interconnections without fiber congestion. We propose a scheme for constructing a large-scale shuffler capable of permuting interconnected fibers that employs plural optical fiber sheets, and for arranging optical fibers without congestion in racks. We constructed a 16,384-fiber shuffler system with sixty-four 256-fiber shuffler sheets and 16-fiber fiber physical contact (FPC) connectors for a 128 x 128 switch system with 1 x 128 planar lightwave circuit (PLC) type thermo-optic switches (TOSW). Input here the part of summary.
Archive | 2003
Ritsu Tech Re Lab Kawase; Kyoichi Tech Re Lab Sasaki; Masayoshi Suzuki; Tech Re Lab Tatsushi Kobayashi; Ryo Nagase; Mamoru Hirayama
Archive | 2001
Ritsu Kawase; Ken Sukegawa; Tatsushi Kobayashi; Koichi Arishima; Mamoru Hirayama
Archive | 2000
Mamoru Hirayama; Koichi Arishima; Tsuneo Tamagaki; Masayuki Sasaki; Chikao Nakagawa
Archive | 2000
Koichi Arishima; Mamoru Hirayama; Chikao Nakagawa; Masayuki Sasaki; Tsuneo Tamagaki; 親生 中川; 雅之 佐々木; 守 平山; 功一 有島; 恒男 玉垣
Archive | 2000
Mamoru Hirayama; Koichi Arishima; Shin Sumida
Archive | 1998
Koichi Arishima; Mamoru Hirayama; Tatsushi Kobayashi; Takeshi Sukegawa; 健 助川; 辰志 小林; 守 平山; 功一 有島
Archive | 1998
Koichi Arishima; Mamoru Hirayama; Masaru Kobayashi; Makoto Sumita; Yoshiaki Takeuchi; Takuji Yoshida; 真 住田; 卓史 吉田; 勝 小林; 守 平山; 功一 有島; 善明 竹内
Archive | 1997
Koichi Arishima; Shuichiro Asakawa; Mamoru Hirayama; Masaru Kobayashi; 勝 小林; 守 平山; 功一 有島; 修一郎 浅川