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Showing papers by "Yohei Sakamaki published in 2012"

Journal Article•DOI•
All-in-One 112-Gb/s DP-QPSK Optical Receiver Front-End Module Using Hybrid Integration of Silica-Based Planar Lightwave Circuit and Photodiode Arrays

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Takaharu Ohyama1, Ogawa Ikuo1, Hiromasa Tanobe1, Ryoichi Kasahara1, Satoshi Tsunashima1, Toshihide Yoshimatsu1, Hiroyuki Fukuyama1, Toshihiro Itoh1, Yohei Sakamaki1, Yoshifumi Muramoto1, Hiroto Kawakami2, Mitsuteru Ishikawa2, Shinji Mino1, Koichi Murata1 •
Nippon Telegraph and Telephone1, Harvard University2
15 Apr 2012-IEEE Photonics Technology Letters
TL;DR: In this paper, a hybrid integrated optical front-end module for a 100-Gb/s-class coherent receiver using silica-based planar lightwave circuit (PLC) technology is proposed.
Abstract: We propose a new hybrid integrated optical front-end module for a 100-Gb/s-class coherent receiver using silica-based planar lightwave circuit (PLC) technology. We have developed an integrated structure composed of multichannel microcollimator optics between PLC waveguides and photodiodes (PDs), and compact hermetically sealed optical-to-electrical converters with a PD array and a transimpedance amplifier array to maintain reliability. We used the technology to fabricate an all-in-one optical front-end module for a dual polarization quadrature phase-shift-keying (DP-QPSK) coherent receiver, and confirmed that the module operated successfully for 112-Gb/s DP-QPSK signal detection.

14 citations

Patent•
Optical switch system

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Yohei Sakamaki, Mitsunori Fukutoku, Tomoyoshi Kataoka, Tetsuo Takahashi, Sawara Akio, Shunichi Soma 
02 Aug 2012
TL;DR: An optical switch system is composed of a plurality of optical switches, and includes a mechanism that can change an optical connection method between the optical switches and an optical switch module control section as discussed by the authors.
Abstract: PROBLEM TO BE SOLVED: To provide an optical switch system capable of eliminating necessity of individual design and manufacture even when a combination of an optical switch function on an optical switch system changes and achieving short development period and cost reduction.SOLUTION: An optical switch system is composed of a plurality of optical switches and includes a mechanism that can change an optical connection method between the optical switches and an optical switch module control section that can change a control method for the optical switch.

2 citations

Proceedings Article•DOI•
Simultaneous and adaptive DPSK dense WDM monitoring using sequential ultrafast field sampling

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Okamoto Tatsuya1, Keiji Okamoto1, Fumihiko Ito1, Yohei Sakamaki1, Toshikazu Hashimoto1 •
Nippon Telegraph and Telephone1
04 Mar 2012
TL;DR: This work introduces a dual-channel sampling technique for WDM signal observation that uses sequential ultrafast field sampling to observe DPSK WDM signals and successfully observed an 8 channel × 25 Gbit/s signal.
Abstract: We introduce a dual-channel sampling technique for WDM signal observation that uses sequential ultrafast field sampling to observe DPSK WDM signals. An 8 channel × 25 Gbit/s signal is successfully observed for the first time.

1 citations