1
Chihiro Ohshima, Susumu Kinoshita, Terumi Chikama: Optical amplifier for use in optical communications equipment. Fujitsu, Staas & Halsey, April 16, 2002: US06373623 (22 worldwide citation)

The output level of pumping light supplied from a pumping light source is varied using a variable attenuator, which is controlled by a variable attenuator driver circuit. By separating a portion containing the pumping light source from a portion containing an amplification medium, it becomes possibl ...


2
Chihiro Ohshima, Yasushi Sugaya: Optical amplifying apparatus and optical communication system. Fujitsu, Staas & Halsey, October 8, 2002: US06462861 (18 worldwide citation)

The present invention aims at providing an optical amplifying apparatus constituted by combining Raman amplifiers, in which deterioration of a signal/noise ratio of output light is prevented to thereby improve the transmission characteristic of signal light, and an optical communication system utili ...


3
Chihiro Ohshima, Susumu Kinoshita, Terumi Chikama: Optical amplifier for use in optical communications equipment. Fujitsu, Staas & Halsey, January 1, 2002: US06335823 (10 worldwide citation)

The output level of pumping light supplied from a pumping light source is varied using a variable attenuator, which is controlled by a variable attenuator driver circuit. By separating a portion containing the pumping light source from a portion containing an amplification medium, it becomes possibl ...


4
Chihiro Ohshima: Optical amplifier for use in optical communications equipment. Fujitsu, Staas & Halsey, November 20, 2001: US06320694 (8 worldwide citation)

The output level of pumping light supplied from a pumping light source is varied using a variable attenuator, which is controlled by a variable attenuator driver circuit. By separating a portion containing the pumping light source from a portion containing an amplification medium, it becomes possibl ...


5
Hiroaki Tomofuji, Motoyoshi Sekiya, Takeshi Sakamoto, Makoto Murakami, Chihiro Ohshima, Yoshihito Onoda: Optical amplifying apparatus, wide-band optical amplifying apparatus, and optical communication system. Fujitsu, Staas & Halsey, June 25, 2002: US06411429 (8 worldwide citation)

An optical amplifying apparatus for widening the input dynamic range and lowering noises. The optical amplifying apparatus comprises a first optical amplifier, an optical attenuator, a second optical amplifier and a controller. The first optical amplifier changes the target value of output light whe ...


6
Susumu Kinoshita, Miki Onaka, Yasushi Sugaya, Chihiro Ohshima, Terumi Chikama, Hiroyuki Itou, Tadashi Okiyama, Taiki Kobayashi: Optical amplifier. Fujitsu, Staas & Halsey, December 17, 2002: US06496300 (7 worldwide citation)

An optical amplifier of a wavelength-division multiplexing transmission system that includes a pre-stage optical amplifying unit and a post stage optical amplifying unit. The pre-stage optical amplifying unit has a rare-earth element doped optical fiber and a pump light source for inputting a pump l ...


7
Chihiro Ohshima, Etsuko Hayashi: Amplification method and optical amplifier for wavelength division multiplexed signal light. Fujitsu, Staas & Halsey, October 10, 2006: US07119950 (2 worldwide citation)

In an optical amplifier of the invention, a WDM signal light is separated into N components by a demultiplexer after which each component is amplified by N optical amplifier sections, and the output light level of each optical amplifier section is controlled to a constant level by respective control ...


8
Susumu Kinoshita, Miki Onaka, Yasushi Sugaya, Chihiro Ohshima, Terumi Chikama, Hiroyuki Itou, Tadashi Okiyama, Taiki Kobayashi: Optical amplifier. Fujitsu, Staas & Halsey, March 7, 2002: US20020027703-A1 (1 worldwide citation)

An optical amplifier of a wavelength-division multiplexing transmission system that includes a pre-stage optical amplifying unit and a post stage optical amplifying unit. The pre-stage optical amplifying unit has a rare-earth element doped optical fiber and a pump light source for inputting a pump l ...


9
Chihiro Ohshima, Susumu Kinoshita, Terumi Chikama: Optical amplifier for use in optical communications equipment. Staas & Halsey, July 19, 2001: US20010008459-A1 (1 worldwide citation)

The output level of pumping light supplied from a pumping light source is varied using a variable attenuator, which is controlled by a variable attenuator driver circuit. By separating a portion containing the pumping light source from a portion containing an amplification medium, it becomes possibl ...


10
Chihiro Ohshima, Susumu Kinoshita, Terumi Chikama: Optical amplifier for use in optical communications equipment. Staas & Halsey, December 13, 2001: US20010050805-A1 (1 worldwide citation)

The output level of pumping light supplied from a pumping light source is varied using a variable attenuator, which is controlled by a variable attenuator driver circuit. By separating a portion containing the pumping light source from a portion containing an amplification medium, it becomes possibl ...