Fujitsu Corporation

Other

Shigeki Watanabe

Fumio Futami

Tomoyuki Kato

Takeshi Hoshida

Ryou Okabe

Takao Naito

Terumi Chikama

Tetsuya Kiyonaga

George Ishikawa

Yoshihito Onoda

Shunsuke Ono

Shinichi Takeda

Hiroki Ooi

Yuichi Akiyama

Takahito Tanimura

Rainer Hainberger

Hideo Kuwahara

Hiroshi Onaka

Yutaka Kai

Yutaka Takita

Toshiki Tanaka

Hideyuki Miyata

Tomoo Takahara

Masato Nishihara

Hiroshi Nakamoto

Kazuo Hironishi

Yuji Tamura

Tomohiro Yamauchi

Masataka Nakazawa

Yu Tanaka

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

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.

Transmission apparatus, reception apparatus, and method for estimating characteristics of transmission line

A wavelength conversion device that converts input signal light having a first frequency into output signal light having a second frequency, includes: a control-light generator that outputs first continuous oscillation light and second continuous oscillation light; and a nonlinear optical medium that cross-phase modulates the input signal light with the first continuous oscillation light and the second continuous oscillation light and generates the output signal light, wherein the control-light generator outputs the first continuous oscillation light and the second continuous oscillation light to have polarized waves in directions orthogonal to each other and have a frequency interval equal to a difference between the first frequency and the second frequency and controls, based on intensity of the output signal light, timings of modulation of phases of the first continuous oscillation light and the second continuous oscillation light to be aligned with each other.

Wavelength conversion device, control-light generation device, wavelength conversion method, and control-light generation method

An optical modulator combines and inputs a signal light propagating through the optical network and a control light having information concerning the optical network to a nonlinear optical medium. The optical modulator modulates the signal light according to changes in intensity of the control light, in the nonlinear optical medium.

Optical signal-processing apparatus, receiving apparatus, and optical network system

An apparatus includes a light source that causes continuous oscillation light to enter one terminal of an optical transmission line, wherein the continuous oscillation light is to propagate a light variation of a first physical amount generated on the optical transmission line to another terminal of the optical transmission line; a photodetector that detects, on the one terminal, light turned back from a light modulation converter provided on the another terminal, wherein the light modulation converter obtains the turned-back light by converting the light variation of the first physical amount into a light variation of a second physical amount; and a processor that calculates a light-variation location generated on the optical transmission line by comparing time variations in the light variation of the first physical amount and the light variation of the second physical amount in the light detected by the photodetector.

Location measurement apparatus, light modulation converter, and light variation location measurement method

In an optical network system: control light is generated by optical modulation based on a modulated data signal which is generated by modulation of a carrier signal with a data signal; and the control light is optically combined with an optical carrier which is to propagate through a nonlinear optical medium, so as to cause cross phase modulation of the optical carrier with the control light in the nonlinear optical medium.

Optical-signal processing apparatus, optical transmission method, receiver, and optical network system

OADM processes input light containing reference light and multiplexed optical signals. A splitter splits the input light to generate first and second input light. A receiver generates an electric signal representing the second input light. An estimator estimates a difference in optical frequency between the reference light and a specified optical signal based on the electric signal. Alight source generates first and second light. An optical frequency of the second light is shifted by the estimated difference with respect to that of the first light. A demodulator generates a dropped signal representing the specified optical signal. A drive signal generator generates a drive signal in accordance with an inverted signal of the dropped signal. A modulator modulates the second light with the drive signal to generate a modulated optical signal. The first input light, the first light and the modulated optical signal are input to non-linear optical medium.

Optical add/drop multiplexer and method for adding/dropping optical signal

An optical-frequency shift device to shift a first optical-signal of a first optical-frequency to a second optical-signal of a second optical-frequency, including a splitter to split the first optical-signal to optical-signals of first and second polarizations, orthogonal each other, a generator to generate first and fourth controlled-light of the first polarization, and second and third controlled-light of the second polarization, each of frequency differences between the first and second controlled-light and between the third and fourth controlled-light having a spacing equal to a difference between the first and second optical-frequencies, a nonlinear optical-medium in which idler light of the second and first polarization are created by causing cross phase modulation of the optical-signals of the first and second polarizations, the first and third controlled-light, and the second and fourth controlled-light, respectively, and an optical-combiner to combine the idler light of the second and first polarization.

Optical frequency shift device and method

A relay device includes: a first port, a plurality of second ports, a splitter configured to branch first optical signals input from the first port into the plurality of second ports; and a plurality of optical modulators configured to modulate shared carrier light by multiplexing the carrier light with a plurality of second optical signals with different frequencies input from the plurality of second ports and by inputting the multiplexed carrier light into a plurality of nonlinear optical mediums, and to transmit the carrier light to the first port.

Relay device and optical network system

Input light includes a multicarrier signal and first CW light of a first optical frequency. A transmitter generates a modulated optical signal based on an inverted signal of a dropped signal. A light source generates second CW light of a second optical frequency. A delay element adjusts a phase difference between the modulated optical signal and the second CW light. The multicarrier signal, the first CW light, the modulated optical signal and the second CW light are input to nonlinear optical medium. A detector detects beat frequency component between the modulated optical signal and the second CW light. A controller controls the delay element so as to increase the beat frequency component. A difference between the first optical frequency and an optical frequency of the dropped optical signal is substantially the same as a difference between the second optical frequency and an optical frequency of the modulated optical signal.

Optical add-drop multiplexer

An optical multiplexing includes: a monitor configured to detect power of an optical component including a frequency component of a cross point between spectra of a first sub-carrier signal and a second sub-carrier signal; and a controller configured to control a modulation timing of a data symbol of the second sub-carrier signal according to the power detected by the monitor, wherein the second sub-carrier signal is multiplexed to a carrier to be adjacent to the first sub-carrier signal multiplexed to the carrier so as to generate an optical Orthogonal Frequency Divisional Multiplexing (OFDM) signal in which an interference between the first and second sub-carrier signals is suppressed.

Growing community of inventors

Kawasaki, Japan

Shigeki Watanabe