1
Kosuke Komaki, Hiroyuki Itou, Hiroshi Iizuka: Optical amplifier and control method therefor. Fujitsu, Staas & Halsey, December 20, 2005: US06977770 (7 worldwide citation)

The optical amplifier according to the present invention includes a first optical amplifying unit, a second optical amplifying unit, a variable optical attenuator optically connected between the first and second optical amplifying units and a first control unit for controlling the gains of the first ...


2
Kosuke Komaki, Hiroyuki Itoh: Optical amplifier. Fujitsu, Staas & Halsey, May 8, 2007: US07215464 (7 worldwide citation)

Optical amplifier which can eliminate the need for an optical detection section before an external attenuating medium, can prevent SN degradation, and can reduce power required for pumping light. An attenuation amount detection section detects an amount of signal light attenuation caused by a variab ...


3
Kosuke Komaki, Masahiro Shioda, Katsumi Fukumitsu, Osamu Takeuchi: Optical receiver. Fujitsu, Fujitsu Patent Center, July 2, 2013: US08478137 (5 worldwide citation)

An optical receiver includes: a waveform distortion compensator to perform an operation on digital signal representing an optical signal generated by an A/D converter to compensate for waveform distortion of the optical signal; a phase detector to generate phase information representing sampling pha ...


4
Hiroyuki Itoh, Kosuke Komaki: WDM optical transmission system and optical amplifying apparatus. Fujitsu, Fujitsu Patent Center, March 1, 2011: US07899331 (5 worldwide citation)

According to a WDM optical transmission system of the present invention, wavelength numbers information of a WDM signal light output from an upstream side optical amplifying unit to a transmission path fiber, and signal output level information thereof are transmitted to a downstream side optical am ...


5
Yuichirou Sakamoto, Kosuke Komaki: Digital coherent receiver and digital coherent reception method. Fujitsu, Staas & Halsey, March 11, 2014: US08670678 (4 worldwide citation)

A digital coherent receiver converts signals and local light respectively detected, as detection results, in signal light from an optical transmission line, into digital signals and that further applies digital processing to the digital signals. The receiver includes a skew detecting unit that detec ...


6
Hiroki Oi, Kosuke Komaki: Optical transmission device. Fujitsu, Staas & Halsey, August 30, 2016: US09432113 (3 worldwide citation)

An optical transmission device including a wavelength selective switch including plural output ports, an optical intensity monitoring device that receives each optical signal output from the plural output ports of the wavelength selective switch and monitors the optical intensity of the optical sign ...


7
Hiroshi Iizuka, Kosuke Komaki, Hiroyuki Itou: Optical amplifier and optical amplifier control method. Fujitsu, Katten Muchin Rosenman, April 10, 2007: US07202997 (3 worldwide citation)

An optical amplifier includes first and second optical amplifier units, a variable optical attenuator optically coupled between the first and second optical amplifier units, a first control unit to control gains of the first and second optical amplifier units based on an input of the first optical a ...


8
Masao Nakata, Kosuke Komaki, Yoshio Shimano: Optical amplifier. Fujitsu, Staas & Halsey, December 5, 2006: US07145717 (3 worldwide citation)

An optical amplifier that improves transmission quality by driving an excitation light source according to a change in the level of an input optical signal and by compensating for a change in the characteristics of the excitation light source. An optical amplification section includes an amplificati ...


9
Hisao Nakashima, Takeshi Hoshida, Kosuke Komaki: Digital coherent receiver and receiving method. Fujitsu, Fujitsu Patent Center, February 25, 2014: US08660438 (3 worldwide citation)

A digital coherent receiver includes a front end, an A/D convertor, and a processor. The front end converts a light signal into an electric signal by using a signal light and a local oscillator light. The A/D convertor converts the electric signal of the front end into a digital signal. The processo ...


10
Taku Saito, Kosuke Komaki, Taketo Endo: Optical transmission system, optical transmission apparatus and wavelength spacing measurement apparatus. Fujitsu, Staas & Halsey, July 4, 2017: US09698905 (2 worldwide citation)

An optical transmission system includes comprising: a first optical transmission apparatus to transmit wavelength-multiplexed optical signals; and a second optical transmission apparatus to receive the wavelength-multiplexed optical signals, the second optical transmission apparatus including: a rec ...