Fujitsu Corporation

Fujitsu Ten Limited

Tomoyuki Kato

Shigeki Watanabe

Takeshi Hoshida

Goji Nakagawa

Tomohiro Yamauchi

Takahito Tanimura

Yutaka Kai

Toshiki Tanaka

Tomoo Takahara

Norifumi Shukunami

Masato Nishihara

Tomoaki Takeyama

Makoto Hasegawa

Shota Mori

Fumio Futami

Ryou Okabe

Masaaki Kawai

Shinya Tanaka

Shogo Tanaka

Shinji Komiya

Shinsuke Matsumoto

Motoya Jiyama

Junji Ito

Naoki Sugamoto

Shinichi Sato

Atsushi Yamawaki

Takahiro Nishimura

Atsushi Ohtaki

Tomohito Kato

Takeshi Dowa

Shingo Matsuda

Yu Tanaka

A wavelength conversion device includes: a first wavelength conversion circuit that wavelength-converts, by passing first multiplex light obtained by multiplexing an optical signal of a first wavelength band from each transmitter through an inside of a wavelength conversion medium by using excitation light, the first multiplex light into second multiplex light in a second wavelength band different from the first wavelength band; and a first generation circuit that generates a first control signal that controls each transmitter to shift a signal wavelength of each optical signal in the first multiplex light before wavelength conversion according to a subsequent part to which the second multiplex light after wavelength conversion in the first wavelength conversion circuit is input, and transmits the first control signal to each transmitter.

Wavelength conversion device, transmission device, and transmission system

A wavelength converter includes a polarization beam splitter configured to separate input light into a first polarization and a second polarization that are orthogonal to each other a non-linear optical medium configured to include a first incident end on which the first polarization separated by the polarization beam splitter is incident and a second incident end on which the second polarization separated by the polarization beam splitter is incident at a position different from a position of the first incident end, an optical multiplexer configured to multiplex the first polarization that has passed through the non-linear optical medium and the second polarization that has passed through the non-linear optical medium, and an optical element arranged between the non-linear optical medium and the optical multiplexer, and configured to correct a polarization axis of at least one of the first polarization and the second polarization incident on the optical multiplexer.

Wavelength converter, optical transmission system and wavelength conversion method

An optical communication device includes an excitation light source that outputs excitation light, a multiplexer that multiplexes signal light and the excitation light outputted from the excitation light source, a first nonlinear optical medium into which the multiplexed excitation light and the signal light are inputted, and a second nonlinear optical medium that is coupled to the first nonlinear optical medium in series and has an optical property different from that of the first nonlinear optical medium.

Optical communication device, optical transmission system, wavelength converter, and optical communication method

An optical transmission device includes a first wavelength multiplexer, a second wavelength multiplexer, a wavelength converter and a third wavelength multiplexer. The first wavelength multiplexer multiplexes optical signals in a first wavelength band to generate first wavelength multiplexed light. The second wavelength multiplexer multiplexes optical signals in the first wavelength band to generate second wavelength multiplexed light in a first polarization. The wavelength converter converts a wavelength of the second wavelength multiplexed light from the first wavelength band into a second wavelength band by a cross phase modulation among the second wavelength multiplexed light, first pump light in a second polarization and second pump light in the second polarization. The second polarization is orthogonal to the first polarization. The third wavelength multiplexer multiplexes the second wavelength multiplexed light whose wavelength has been converted by the wavelength converter and the first wavelength multiplexed light.

Wavelength converter and optical transmission device that includes wavelength converter

A transmission device including a demultiplexer configured to demultiplex a multiplexed light obtained by multiplexing the plurality of wavelength division multiplexing (WDM) optical signals including different wavelength bands into the plurality of WDM optical signals, a plurality of optical amplifiers configured to amplify the plurality of WDM optical signals, respectively, a wavelength converter configured to convert a first wavelength band of the wavelength bands of at least a first WDM optical signal of the plurality of WDM optical signals amplified by the plurality of optical amplifiers into a second wavelength band of the wavelength bands of a second WDM optical signal of the plurality of WDM optical signals so that the second wavelength band does not overlap among the wavelength bands, and a multiplexer configured to multiplex the plurality of WDM optical signals which include the wavelength bands converted by the wavelength converter.

Transmission device, transmission method, and transmission system

A wavelength conversion device includes a nonlinear optical medium and a controller. The nonlinear optical medium configured to generate light from signal light and excitation light, the excitation light having a wavelength different from a wavelength of the signal light and having a second electric field strength than a first electric field strength of the signal light, the light having a wavelength different from a wavelengths of the signal light and the excitation light. The controller configured to control a first temperature of the nonlinear optical medium based on an intensity of the light.

Wavelength conversion device and wavelength conversion method

A wavelength converter that converts signal light and pump light into a light containing a new wavelength component using a nonlinear optical fiber, has a PBS for splitting incident light into a first polarized wave and a second polarized wave, a first polarization controller provided between the PBS and a first end of the nonlinear optical fiber, and a second polarization controller provided between the PBS and a second end of the nonlinear optical fiber, wherein in an optical loop connecting the PBS, the first polarization controller, the nonlinear optical fiber and the second polarization controller, the first polarized wave and a first component of the pump light travel through the nonlinear optical fiber in a first direction, and the second polarized wave and a second component of the pump light travel through the nonlinear optical fiber in a second direction opposite to the first direction.

Wavelength converter and fiber optic transmission system

A wavelength conversion device includes a wavelength converter converts a wavelength band of a wavelength-division multiplex signal, a first wavelength filter transmits the wavelength-division multiplex signal on an input side of the wavelength converter, a second wavelength filter transmits the wavelength-division multiplex signal on an output side of the wavelength converter, and a controller controls a temperature of the wavelength converter such that a difference between a ratio of power of the wavelength-division multiplex signal which is not transmitted through the first wavelength filter on the input side to power of the wavelength-division multiplex signal which have been transmitted through the first wavelength filter on the input side and a ratio of a power of the wavelength-division multiplex signal which is not transmitted through the second wavelength filter on the output side to power of the wavelength-division multiplex signal which have been transmitted through the second wavelength filter.

A method includes multiplexing signal light of first polarization and excitation light, and multiplexing signal light of second polarization, which is perpendicular to the first polarization, and the excitation light, modulating the signal light of the first polarization before the wavelength conversion, and reducing a modulation component in signal light after wavelength conversion, modulating the signal light of the second polarization before the wavelength conversion, and reducing the modulation component in the signal light after the wavelength conversion, and multiplexing the signal light of the first polarization after the wavelength conversion and the signal light of the second polarization after the wavelength conversion.

Wavelength conversion device and method of performing wavelength conversion

A transmission apparatus includes a first multiplexer configured to multiplex light of wavelengths of a first wavelength band to output first wavelength multiplex light, a first wavelength converter configured to convert the first wavelength multiplex light into wavelengths of a second wavelength band which is different from the first wavelength band, by using first excitation light, a second multiplexer configured to multiplex light of wavelengths of the first wavelength band which are different from the wavelengths of the first wavelength multiplex light to output second wavelength multiplex light, a second wavelength converter configured to convert the second wavelength multiplex light into wavelengths of the second wavelength band, by using second excitation light, a third multiplexer configured to multiplex the first wavelength multiplex light converted into the wavelengths of the second wavelength band, and the second wavelength multiplex light converted into the wavelengths of the second wavelength band.

Transmission apparatus and transmission method

A wavelength converter includes an excitation light source outputting excitation light, a beam splitter receiving an input of the excitation light and an input of the optical signal and to divide both the inputted excitation light and the inputted optical signal into a first polarization component and a second polarization component, a non-linear optical fiber as a non-polarization-maintaining fiber, an accommodation section securing and accommodating the non-linear optical fiber, a first collimator lens disposed between the beam splitter and a first end of the non-linear optical fiber, and a second collimator lens disposed between the beam splitter and a second end of the non-linear optical fiber, wherein the optical signal is inputted to the beam splitter from a direction different from the input of the excitation light.

Wavelength converter and transmission apparatus

A wavelength converter includes a first phase modulator configured to perform phase modulation on pump light in accordance with a first phase modulation signal, a second phase modulator configured to perform phase modulation on signal light in accordance with a second phase modulation signal, a wavelength converter configured to multiplex the signal light having undergone the phase modulation with the pump light having undergone the phase modulation, the wavelength converter configured to perform wavelength conversion on the signal light in accordance with the pump light, a detector configured to detect a modulation component from the signal light having undergone the phase modulation and the pump light having undergone the phase modulation, and a generator configured to generate the first phase modulation signal and the second phase modulation signal so as to minimize the detected modulation component.

Wavelength converter apparatus and method of performing wavelength conversion

A compensating device includes at least one detector configured to detect intensity variation of the optical signal, at least one filter configured to extract a band where most of the optical phase distortion is generated from a component of the intensity variation of the optical signal, a control circuit configured to generate, based on the extraction with the at least one filter, a compensation signal exhibiting temporal intensity variation of the input optical signal, at least one compensation signal light source configured to output, based on the compensation signal of a controller, a compensation signal light exhibiting intensity variation in opposite phase to the temporal intensity variation of the input optical signal and having a different wavelength from a wavelength of the optical signal and an optical multiplexer configured to output to a transmission path a signal light formed by combining the optical signal and the compensation signal light.

Optical phase distortion compensating device and method of compensating optical phase distortion

There is provided a transmission apparatus including a transmitter configured to modulate a signal to a first signal having a first wavelength and a signal to a second signal having a second wavelength, and transmit the first signal and the second signal to a transmission line so that the second signal is varied in accordance with variation in an amount of cross phase modulation of the first signal passing through each position on the transmission line, and a signal processor configured to include at least one of a logic device and a processor, and configured to add an amount of chromatic dispersion at which a remaining amount of chromatic dispersion of the first wavelength at a certain position on the transmission line is equal to zero to the first wavelength in the transmission of the first signal and the second signal.

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Yokohama, Japan

Tomoyuki Kato