Fujitsu Corporation

Fujitsu Optical Components Limited

Toshihiro Ohtani

Tsukasa Takahashi

Yoshinobu Kubota

Futoshi Izumi

Yuichi Suzuki

Shota Mori

Hideki Kobayashi

Yasuhiro Omori

Tomoyuki Itoh

Masaki Sato

Miki Onaka

Norifumi Shukunami

Yoichi Oikawa

Takehito Tanaka

Masahiro Yuki

Ryosuke Goto

Kenichi Sasaki

Tatsuya Tsuzuki

Yuji Tamura

Hiroyuki Deguchi

Makoto Murakami

Eiji Ishikawa

Tomoyuki Ito

Masaki Satoh

Ryuta Hoshi

Hiroto Ikeda

Yuki Sakurai

Yoshihisa Kondo

Kazuyuki Wakabayashi

Tomotaka Otani

Yukiko Sakai

A disclosed electronic device includes a graphite laminate having a plurality of layers laminated in a first direction, each layer containing graphite, where the graphite laminate has a portion in a stepwise form in which edges of the plurality of layers are offset from each other.

Electronic device

An optical communications device includes a support, a plate-shaped member, and an optical cable. The plate-shaped member is supported in a curved state on the support. The plate-shaped member is a flexible printed circuit including a flexible substrate and a metallic pattern formed on the flexible substrate. The optical cable is provided along a curved surface of the plate-shaped member on the support.

Optical communications device having a plate-shaped flexible printed circuit with metallic pattern

An optical adapter includes: a housing having a plurality of openings on each of opposite end surfaces thereof; a plurality of ports formed in parallel with each other inside the housing and each extending to form one of the openings on each of the opposite ends surfaces, an optical connector being inserted into each of the openings; and a shutter part installed at each of the ports such that when the optical connector is inserted into an opening of one end of the port, the shutter part leans back to a retreat position that passes light emitted from the optical connector inserted into an opening of another end of the port, when the optical connector is pulled out of the opening of the one end of the port, the shutter part is raised up from the retreat position to a blocking position that blocks the emitted light.

Optical adapter

An arrayed optical amplifier includes: at least one first amplifier including a first excitation light source controlled to a first temperature; at least one second amplifier including a second excitation light source controlled to a second temperature different from the first temperature; and a control circuit coupled to the at least one first amplifier and the at least one second amplifiers.

Arrayed optical amplifier and optical transmission device

An amplifying device includes a light source configured to output excitation light, a depolarizer configured to change a degree of polarization of the excitation light in accordance with a setting, an amplifier configured to execute Raman amplification so as to amplify a polarized multiplexed optical signal by the excitation light of which the degree of the polarization has been changed by the depolarizer, a measurer configured to measure the power of a plurality of polarized light components multiplexed into the polarized multiplexed optical signal subjected to the Raman amplification and amplified by the excitation light, and an adjuster configured to calculate differences between the power of the plurality of polarized light components and adjust the setting of the depolarizer so as to reduce the differences between the power of the plurality of polarized light components.

Amplifying device, receiving device, and amplification method

An OCM monitors a plurality of SW ports each receiving an optical signal by switching the SW ports. The OCM includes a PD, a control circuit, and an arithmetic circuit. The PD detects an optical power level on wavelengths spaced at predetermined intervals in each of the SW ports to be monitored. The control circuit determines, in each of the SW ports, whether arithmetic processing using a waveform estimated from the optical power level is executed, depending on presence or absence of a change in the optical power level detected by the PD. The arithmetic circuit performs the arithmetic processing by using the waveform when the control circuit determines execution of the arithmetic processing.

Port monitoring device and port monitoring method

A tunable dispersion compensation device includes a plurality of tunable dispersion compensators coupled in series, a controller configured to control an amount of chromatic dispersion to be set in each of the plurality of tunable dispersion compensators, and a table including a correspondence relationship between an amount of chromatic dispersion and a wavelength band, for each of the plurality of tunable dispersion compensators, wherein the controller decides an amount of chromatic dispersion to be set in each of the plurality of tunable dispersion compensators, based on a total amount of chromatic dispersion desired for the plurality of tunable dispersion compensators and the correspondence relationship included in the table so that a difference between bandwidths of a first tunable dispersion compensator having the widest wavelength band and a second tunable dispersion compensator having the narrowest wavelength band, among the plurality of tunable dispersion compensators, is within a given range.

Tunable dispersion compensation device, optical reception apparatus, and method for controlling tunable dispersion compensation

An optical transmission device includes an extractor that extracts respective optical signals from optical signals multiplexed from a plurality of optical signals of different wavelengths, a detector that detects wavelengths of the extracted respective optical signals, a storage that stores the wavelengths of the detected respective optical signals, and a processor that is operative to derive trends in wavelength variation of the respective optical signals based on the detected respective optical signals and the respective optical signals stored in the storage, and determines that either one or both of the extractor and the detector cause the wavelengths to be varied when the trends in wavelength variation of two or more wavelengths are the same.

Optical transmission device, optical transmission system and optical transmission method

There is provided an optical transmission receiver includes an optical switch configured to switch between optical transmission channels, the optical transmission channels being gradually switched from one to the other, an optical amplifier configured to amplify a light propagating in the other of the optical transmission channels which is in a state subsequent to switching, and a switching speed controller configured to control a switching speed of the optical switch based on a level of the light amplified by the optical amplifier.

Optical transmission receiver and method for the same

An optical transmission device includes: a variable dispersion compensator to give chromatic dispersion and output an input light, a branching unit to branch the light output from the variable dispersion compensator to a first part and a second part, a reproduction unit to reproduce an electric signal from the first part of the input light, a monitor unit to perform reproducing processing on the electric signal from the second part of the input light, control the variable dispersion compensator based on a result of the reproducing processing, and has a sensitivity to a variation of the chromatic dispersion which is higher than the sensitivity to the variation of the chromatic dispersion of the reproduction unit.

Optical transmission device, transmission and reception module, optical transmission system, and wavelength dispersion compensation method in optical transmission device

A dispersion compensating apparatus includes a tunable dispersion compensator that dispersion-compensates an optical signal using a group delay property that is asymmetrical in bands outside an effective band; a set device that sets a dispersion compensation amount in the tunable dispersion compensator; and a shifter that shifts a central frequency of the effective band of the tunable dispersion compensator, based on the dispersion compensation amount set by the set device.

Dispersion compensating apparatus, dispersion compensating method, optical receiving apparatus, and optical receiving method

An optical amplifier module includes a first optical amplifier to amplify main signal light to be supplied to a dispersion compensation fiber (DCF), a second optical amplifier to amplify the main signal light supplied from the DCF, a generating part to generate monitoring light having a wavelength longer than a wavelength of the main signal light, a multiplexing part to multiplex the monitoring light generated by the generating part and the main signal light to be supplied to the DCF, a demultiplexing part to demultiplex the monitoring light from the main signal light supplied from the DCF, and a detection part to detect a light intensity of the monitoring light demultiplexed by the demultiplexing part.

Optical amplifier module and dispersion compensation fiber loss detection method

A wavelength dispersion measurement method includes generating a plurality of test lights in the first terminal, the wavelengths of which are different from a wavelength of a signal light, multiplexing each test light with the signal light and outputting the multiplexed light to the first transmission path, reconverting each electrical signal after converting each beam into electrical signals, multiplexing each test light with the signal light and outputting the multiplexed light to the second transmission path, reconverting each electrical signal after converting each test light into electrical signals, multiplexing each test light with the signal light and outputting the multiplexed light to the first transmission path, measuring times for each test light to be propagated up to a specified number of go-around, and measuring a change of a wavelength dispersion amount in the paths based on a difference between the measured propagation times of each wavelength.

Wavelength dispersion measurement method and device and optical transmission system

A dispersion compensation device includes: an optical branching unit to branch an optical signal to be received; a first dispersion compensator to perform dispersion compensation on one part of the optical signal branched by the optical branching unit with a variable compensation amount; a second dispersion compensator to perform dispersion compensation on another part of the optical signal branched by the optical branching unit; a monitoring unit to monitor the communication quality of an output optical signal of the second dispersion compensator; and a controlling unit to determine the direction of variation in chromatic dispersion of the optical signal based on the direction of variation in communication quality monitored by the monitoring unit and control the compensation amount of the first dispersion compensator based on the result of the determination.

Dispersion compensation device, optical reception device, method for dispersion compensation, and method for optical reception

An optical amplifier apparatus includes an optical amplifier including an amplification medium doped with an active substance, the amplification medium excited in order to amplify light; a semiconductor optical amplifier arranged after the optical amplifier; a driver for supplying a driving current with respect to the semiconductor optical amplifier in order that the semiconductor optical amplifier has an amplification characteristic with respect to an input light, the amplification characteristic including a gain non-saturated region and a gain saturated region; and an input-light level adjuster for adjusting an out put light of the optical amplifier to the input light level of the semiconductor optical amplifier, the input light level being set up between the gain non-saturated region and the gain saturated region.

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Kawasaki, Japan

Toshihiro Ohtani