Nobuhiko Kikuchi: Optical modulator. Hitachi, Antonelli Terry Stout & Kraus, July 12, 2011: US07978390 (41 worldwide citation)

The present invention relates to an optical modulator that generates quaternary amplitude modulated light without inter-symbol-interference by splitting input light into three optical paths, generating a continuous wave signal in a first optical path, generating binary phase modulated lights using a ...

Nobuhiko Kikuchi: Polarization mode dispersion compensator and compensation method. Hitachi, Antonelli Terry Stout & Kraus, December 30, 2003: US06671464 (21 worldwide citation)

The present invention offers a polarization mode dispersion compensator and a compensation method for polarization mode dispersion having simple constitution and being strong against external disturbances. The polarization mode dispersion compensator, a representative example of the present inventio ...

Nobuhiko Kikuchi, Shinya Sasaki: Equipments, transpondor and methods for optical fiber transmission. Hitachi, Antonelli Terry Stout & Kraus, March 11, 2003: US06532320 (21 worldwide citation)

The technical problem disclosed concerns increase of transmission distance between inter-site transmission parts when a circuit speed is increased, and simplification of an intra-site circuit. The means to resolve the problem is as follows. An intra-site circuit connecting an intra-site information ...

Nobuhiko Kikuchi, Shinya Sasaki: Optical transmission system. Hitachi, Kenyon & Kenyon, February 25, 1997: US05606445 (17 worldwide citation)

In an optical transmission system, SPM influences on the degradation of wave forms are canceled by setting an amount of compensation of a dispersion compensator at about 50% of the total amount of dispersion of an optical fiber transmission line so that a received wave form is substantially not vari ...

Nobuhiko Kikuchi, Ryoji Takeyari, Toshiki Sugawara: Optical single sideband transmitter. Hitachi, Antonelli Terry Stout & Kraus, February 1, 2005: US06850713 (13 worldwide citation)

With the normal modulation method, it is difficult to construct a Hilbert transform device because it is complicated. To solve the problem, a single sideband modulated optical pulse train is generated by driving a Mach-Zehnder optical modulator for optical pulse generation with a laser source's sine ...

Nobuhiko Kikuchi, Kenro Sekine, Shinya Sasaki: Optical wavelength add-drop multiplexer. Hitachi Communication Technologies, Stites & Harbison PLLC, Juan Carlos A Marquez Esq, January 26, 2010: US07653311 (12 worldwide citation)

Part of an inputted optical add signal 118 is reflected by a mirror 117, and is thereby inputted into an optical wavelength multiplexer 105 in the reverse direction so that the optical add signal is returned to paths 115-1 through 115-16 corresponding to wavelengths λ1 through λ16. If the returned o ...

Nobuhiko Kikuchi, Ryoji Takeyari: Band-expanding method for optical amplifiers and optical transmission apparatus. Hitachi, Antonelli Terry Stout & Kraus, July 1, 2003: US06587260 (10 worldwide citation)

A method for enabling a pump laser to be added on by means of an optical fiber Raman amplifier and reducing signal degradation to be caused by a gain change to occur after and in the pump laser source add-on process.

Nobuhiko Kikuchi, Shinya Sasaki: Equipments including transponder for optical fiber transmission. Hitachi, Antonelli Terry Stout & Kraus, February 1, 2005: US06850663 (8 worldwide citation)

A transponder which may form part of communication device such as an optical transmitters device includes an optical receiver for receiving a high speed optical information signal and for converting the high speed optical information signal to an electrical signal, a demultiplexing circuit for separ ...

Nobuhiko Kikuchi: Optical field receiver and optical transmission system. Hitachi, Mattingly & Malur PC, May 22, 2012: US08184992 (7 worldwide citation)

An optical field receiver comprises an optical brancher that branches a received optical multilevel signal into first and second optical signals; an optical delayed detector that performs delayed detection on the first optical signal by a delayed detector with a delay time of T/2 (where T is equal t ...

Kohei Mandai, Nobuhiko Kikuchi, Shinya Sasaki: Polarization multiplexing transmitter and transmission system. Hitachi, Mattingly & Malur PC, April 9, 2013: US08417126 (6 worldwide citation)

A polarization multiplexing transmitter which generates polarization-multiplexed signals which are arbitrarily polarization-scrambled at high speed, without adding a polarization modulator and a polarization scrambler. In the transmitter, an orthogonally polarized signal generator includes two optic ...