1
Sugaya Yasushi, Kinoshita Susumu: Controller which controls a variable optical attentuator to control the power level of a wavelength-multiplexed optical signal when the number of channels are varied. Fujitsu, November 5, 1997: EP0805571-A2 (36 worldwide citation)

An optical amplifying apparatus which includes an optical amplifier, an optical attenuator and a controller. The optical amplifier amplifies a light signal having a variable number of channels. The optical attenuator passes the amplified light signal and has a variable light transmissivity. Prior to ...


2
Hayashi Etsuko, Tanaka Tomoto, Sugaya Yasushi, Onaka Miki: Optical amplifier with pump light source control for raman amplification. Fujitsu, February 27, 2002: EP1182808-A2 (16 worldwide citation)

A Raman amplifier for amplifying a wavelength division multiplexed (WDM) light including signal lights wavelength division multiplexed together. The amplifier includes an optical amplifying medium and a controller. The optical amplifying medium uses Raman amplification to amplify the WDM light in ac ...


3
Hayashi Etsuko, Tanaka Tomoto, Sugaya Yasushi, Onaka Yoshinori: Optical amplifier. Fujitsu, March 12, 2002: JP2002-072262 (15 worldwide citation)

PROBLEM TO BE SOLVED: To provide a control algorithm to broaden a frequency band using a plural exciting light wavelengths or excitation light sources when performing Raman amplification, and also to simply perform a constant output power control, a constant gain control, and a wavelength characteri ...


4
Sugaya Yasushi, Chikama Terumi: A remotely pumping type multi-wavelength light transmission system. Fujitsu, September 16, 1998: EP0865173-A2 (13 worldwide citation)

Multi-wavelength light is transmitted from a sending station to a receiving station. An erbium-doped optical fiber is installed on the transmission path that connects the sending station and the receiving station. Pump light is supplied from a light source installed in the receiving station to the e ...


5
Onaka Yoshinori, Tanaka Tomoto, Hayashi Etsuko, Sugaya Yasushi, Kinoshita Susumu: Optical amplifier, optical amplification method and optical amplification system. Fujitsu, March 15, 2002: JP2002-076482 (13 worldwide citation)

PROBLEM TO BE SOLVED: To provide a system for widening the band of an optical amplifier for increasing the wavelength multiplex number and constituting a wide transmission signal band.SOLUTION: Plural optical amplifiers of different optical amplification gain band widths are combined in blocks by us ...


6
Sugaya Yasushi, Muro Shinichirou, Hayashi Etsuko: Raman amplifier. Fujitsu, January 28, 2004: EP1385280-A2 (7 worldwide citation)

Multi-wavelength light, including a plurality of segments of light signal with a different wavelength each, is inputted into a Raman amplification fiber (1). Pumping light generated by a pumping light source (2) is supplied to the Raman amplification fiber (1) in the opposite direction of the transm ...


7
Sugaya Yasushi: Optical equalization and amplification of multi-wavelength light. Fujitsu, August 13, 1997: GB2310094-A (6 worldwide citation)

A variable optical attenuator 1 is provided at the input terminal of a rare-earth doped optical fibre amplifier 2. The attenuator 1 attenuates a multi-wavelength light signal under the control of a circuit 4 such that the signal levels at a variety of wavelengths within the light signal are kept equ ...


8
Kinoshita Susumu, Sugaya Yasushi: Optical amplifier and optical communication system provided with wavelength dispersion compensating function, and wavelength dispersion compensating method for wavelength multiplex signal light. Fujitsu, March 14, 2000: JP2000-078081 (6 worldwide citation)

PROBLEM TO BE SOLVED: To provide an optical amplifier and an optical communication system which are simple in configuration and capable of compensating the wavelength dispersion of the wavelength multiplex signal light of a wide band and to provide a wavelength dispersion compensating method for wav ...


9
Muro Shinichirou, Hayashi Etsuko, Sugaya Yasushi: Method and device for optical amplification. Fujitsu, April 2, 2003: EP1298764-A2 (5 worldwide citation)

The present invention relates to a device for optical amplification, and a primary object of the present invention is to provide a method and device for optical amplification which can maintain the wavelength characteristic of gain constant and can obtain a wide input dynamic range. The device accor ...


10
Sugaya Yasushi: Apparatus for detecting peaks of wavelength-division-multiplexed light, and apparatus for controlling said light. Fujitsu, June 21, 2000: EP1011213-A2 (5 worldwide citation)

Disclosed is an apparatus for controlling wavelength-division-multiplexed light wherein overall power of wavelength-division-multiplexed light is rendered constant through control for uniformalizing the level of only one wave of maximum power, and wherein the levels of respective channels are made s ...