1
George Ishikawa, Hiroshi Nishimoto: Optimized optical transmission system for high capacity transmission. Fujitsu, Helfgott & Karas P C, February 10, 1998: US05717510 (93 worldwide citation)

The invention provides a technique for optimizing transmission conditions to achieve large-capacity transmission, and also provides peripheral techniques for the practical implementation of optical multiplexing that makes large-capacity transmission possible. A transmission characteristic is measure ...


2
George Ishikawa, Hiroshi Nishimoto: Method of and device for driving optical modulator, and optical communications system. Fujitsu, Staas & Halsey, June 29, 1999: US05917637 (70 worldwide citation)

A device and a method for driving an electro-absorption optical modulator for receiving carrier light emitted from a light source and outputting signal light subjected to intensity modulation according to the absorption of the carrier light. A bias circuit generates a bias voltage determined so that ...


3
George Ishikawa, Hiroki Ooi, Naoki Kuwata: Method and apparatus for optimizing dispersion in an optical fiber transmission line in accordance with an optical signal power level. Fujitsu, Staas & Halsey, June 27, 2000: US06081360 (66 worldwide citation)

A method and apparatus for optimizing dispersion in an optical fiber transmission line. The method and apparatus (a) determine an optimum amount of total dispersion of an optical transmission line corresponding to a power level of an optical signal transmitted through the optical transmission line; ...


4
Yuichi Akiyama, George Ishikawa, Hiroki Ooi, Terumi Chikama: Optical transmitter and optical transmission system. Fujitsu, Staas & Halsey, December 9, 2003: US06661974 (43 worldwide citation)

An optical transmitter having a function which compensates for wavelength dispersion is provided with a plurality of light sources for outputting light having wavelengths that differ from one another. Before the optical transmission system begins operating, the wavelength of light output to an optic ...


5
George Ishikawa, Hideyuki Miyata, Hiroshi Onaka, Motoyoshi Sekiya, Kazue Otsuka: Optical wavelength multiplex transmission method and optical dispersion compensation method. Fujitsu, Staas & Halsey, December 9, 1997: US05696614 (42 worldwide citation)

The invention provides an optical wavelength multiplex transmission method wherein a band in the proximity of a zero dispersion wavelength of an optical fiber is used and optical signals are disposed at efficient channel spacings taking an influence of the band, the wavelength dispersion and the fou ...


6
George Ishikawa, Hiroshi Nishimoto, Hiroki Ooi: Optical modulating device and optical modulating method. Fujitsu, Staas & Halsey, July 20, 1999: US05926297 (41 worldwide citation)

An optical modulating method and an optical modulating device for optical time division multiplexing (OTDM). The optical modulating device comprises, for example, an optical switch for generating first and second optical clocks according to a carrier beam output from a light source, optical modulato ...


7
Hiroki Ooi, George Ishikawa, Hiroshi Nishimoto: Control unit for optical modulators producing multiplexed optical output signal. Fujitsu, Helfgott & Karas P C, September 8, 1998: US05805321 (36 worldwide citation)

A control unit for controlling an optically modulating apparatus in an optical transmitter, including plural optical modulators producing an optical output signal consisting of a series of optical pulses for transmitting data under OTDM or WDM, so that pre-chirping magnitudes of the modulators are c ...


8
George Ishikawa, Hiroshi Nishimoto, Hiroki Ooi, Motoyoshi Sekiya, Hiroaki Tomofuji: Optical transmission system with transmission characteristic measuring device. Fujitsu, Helfgott & Karas P C, September 29, 1998: US05815294 (35 worldwide citation)

The invention provides a technique for optimizing transmission conditions to achieve large-capacity transmission, and also provides peripheral techniques for the practical implementation of optical multiplexing that makes large-capacity transmission possible. A transmission characteristic is measure ...


9
George Ishikawa, Hiroshi Nishimoto, Hiroki Ooi, Motoyoshi Sekiya, Hiroaki Tomofuji: Optical transmission system, optical multiplexing transmission system, and related peripheral techniques. Fujitsu, Helfgott & Karas P C, November 23, 1999: US05991477 (32 worldwide citation)

The invention provides a technique for optimizing transmission conditions to achieve large-capacity transmission, and also provides peripheral techniques for the practical implementation of optical multiplexing that makes large-capacity transmission possible. A transmission characteristic is measure ...


10
George Ishikawa, Hideyuki Miyata, Hiroshi Onaka, Motoyoshi Sekiya, Kazue Otsuka: Optical dispersion compensation method for shifting a zero dispersion wavelength of an optical fiber to compensate for dispersion in an optical system. Fujitsu, February 11, 1997: US05602666 (30 worldwide citation)

An optical wavelength multiplex transmission method uses a band around a zero dispersion wavelength of an optical fiber to compensate for waveform degradation, which is produced by a synergetic effect of self phase modulation and chromatic dispersion, to increase transmission distance and transmissi ...