Fujitsu Corporation

Fujitsu Telecom Networks Limited

Shota Mori

Futoshi Izumi

Wataru Kawasaki

Kimio Uekama

Tomoaki Takeyama

Toshihiro Ohtani

Tsukasa Takahashi

Hideki Kobayashi

Mitsuya Kawashita

Takeshi Hoshida

Norifumi Shukunami

Kosuke Komaki

Tomoyuki Kato

Koji Matsunaga

Yasuo Tanaka

Shingo Hara

Tatsuya Toyozumi

Maki Hiraizumi

Kazuhiro Kunimatsu

Reiko Sato

Tooru Matsumoto

Eiji Maeda

Hironobu Fukuura

Jinlin Zhang

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

An optical transmission apparatus includes a wavelength converter that wavelength-converts input signal light using a nonlinear optical medium to output the converted signal light, a memory that holds first information relating to a wavelength conversion characteristic of the wavelength converter, a communication interface that receives second information relating to a second wavelength conversion characteristic of an adjacent optical transmission apparatus, and a control circuit that determines, using the first information and the second information when the second information is received, an excitation light frequency at which a gain deviation of main signal light subjected to a wavelength conversion is minimized to set the determined excitation light frequency in the wavelength converter.

Optical transmission apparatus, optical transmission system, and method of controlling excitation light frequency

A transmission system includes a plurality of nodes in which respective adjacent nodes are coupled by a first kind of optical fiber compatible with light in a first wavelength band or a second kind of optical fiber compatible with light in a second wavelength band, wherein each of the plurality of nodes includes a transmitting node that generates a wavelength-multiplexed optical signal in the first wavelength band by carrying out wavelength multiplexing of a plurality of optical signals and transmits the wavelength-multiplexed optical signal, a receiving node that demultiplexes the plurality of optical signals from the wavelength-multiplexed optical signal and receives the plurality of optical signals, and one or more relay nodes that relay the wavelength-multiplexed optical signal from the transmitting node to the receiving node through the first kind or the second kind of optical fiber.

Transmission system and transmission method

A transmission device includes a control card and a plurality of IF cards. The control card receives first set time from a host PC and calculates second set time by adding add time corresponding to one cycle of a clock signal that is commonly used by the control card and the IF cards to the first set time. The control card distributes the second set time to each of the IF cards. After each of the IF cards receives the second set time and sets the second set time in an internal timer, when a clock signal is detected, each of the IF cards starts a time measuring operation of the internal timer from the second set time.

Transmission device and time synchronization method

An optical amplification device includes: an optical module that outputs an amplified light; and a controller that makes the optical module emit a light when an emission command is input into the controller, wherein the controller cancels an inputting of the emission command until a predetermined time passes, when a protection for forbidding a light emission of the optical module is canceled.

Optical amplification device and method of controlling optical module

A light output control apparatus, includes:

Light output control apparatus

An optical packet switching system includes optical packet switching apparatus and an optical packet transmitting apparatus. The optical packet switching apparatus includes client optical delay units for delaying optical packet signals, network optical delay units for delaying one of the network optical packet signals, the network optical delay unit having a longer delay time than the client optical delay unit, an optical switch unit for switching the route of the inputted client optical packet signal so as to be sent out, an optical switch control unit for controlling the optical switch unit. The optical switch control unit is configured in such a manner as to detect a free time slot. The optical packet transmitting apparatus adjusts transmit timing, with which the client optical packet signal is sent out, in such a manner that the client optical packet signal is inserted into the free time slot.

Optical packet switching system

An excitation light source, for Raman amplification, includes a polarization beam splitter (PBS) for splitting a laser beam from an excitation laser into two polarization components, and a polarization beam combiner (PBC) for combining the two polarization components, and a time difference generator provided between PBS and PBC. The time difference generator generates a difference in propagation time between the two polarization components.

Excitation light source for raman amplification, raman amplifier, and optical transmission system

An optical packet switching device causes branching of an optical packet that is input to an optical switch and detects a synchronization pattern having a predetermined number of bits from the branched optical packet. Then, the optical packet switching device calculates a synchronization point indicating a location of the synchronization pattern with respect to a detection timing and controls, in accordance with the calculated synchronization point, a delay amount of a delay element that delays an optical packet ON signal that is output to the optical switch.

Optical communication device and signal adjusting method

An optical packet switching device is provided with: a first input unit and a second input unit for receiving optical packet signals having destination information and information of a wavelength in use; an optical switch unit for routing the optical packet signals; a branching unit for branching the received optical packet signals; an analyzer unit for analyzing the header of the branched optical packet signals so as to detect the destination information and the information of the wavelength in use; and an output competition determination unit for checking for temporal competition of the optical packet signals based on the destination information and for determining whether the optical packet signals should be transmitted or discarded based on the information of the wavelength in use when there is competition.

Optical packet switching system, optical packet switching device, and optical packet transmitter device

An optical packet transmitter device includes: a detection unit for detecting packet-length information and priority information from a received Ether signal; a setting unit for setting, according to the degree of priority, a division factor by which the Ether signal is divided and a wavelength used for an optical packet signal to be transmitted; a header generation unit for generating a header containing destination information, the packet-length information, the priority information, and information of wavelength in use of the Ether signal; a transmission processing unit for dividing the Ether signal according to the set division factor and generating a plurality of packet signals; a header insertion unit for inserting the generated header in at least one packet signal; and an electrical/optical converter unit for converting the plurality of packet signals into optical packet signals of a plurality of wavelengths according to the set wavelength in use.

Optical packet switching system and optical packet transmitter device

Raman amplifier includes: a pump-light generator configured to supply pump light to a transmission fiber; a measurement circuit configured to measure a relationship between power of the pump light and power of noise output from the transmission fiber with respect to a range from first pump-light power to second pump-light power; a signal detector configured to monitor a supervisory signal in output light of the transmission optical; and a decision unit configured to decide a state of the transmission fiber according to the monitoring result. When the supervisory signal is detected without the pump light, the measurement circuit measures the relationship while increasing the power of the pump light from the first pump-light power. When the supervisory signal is not detected without the pump light, the measurement circuit measures the relationship while decreasing the power of the pump light from the second pump-light power.

Raman amplifier

An optical packet switching device is provided with: a first input unit and a second input unit for receiving an optical packet signal having destination information and priority information; a first demultiplexer and a second demultiplexer for branching the optical packet signal; an optical switch unit for routing one of branched optical packet signals; a first analyzer unit and a second analyzer unit for analyzing the header of the other branched optical packet signal so as to detect the destination information and the priority information; and an output competition determination unit for checking for temporal competition of a plurality of optical packet signals based on destination information and for determining whether the optical packet signals should be transmitted or discarded based on priority information when there is competition.

Optical packet switching system and optical packet switching device

An optical transmission system includes a polarization multiplexing optical transmitter for transmitting an optical signal, where an X-polarized signal and a Y-polarized signal each having a having predetermined frame structure are polarization-multiplexed, to an optical fiber transmission path, and a polarization multiplexing receiver for receiving the optical signal that has propagated through the optical transmission path. The polarization multiplexing optical transmitter delays a frame assignment signal (FAS) in the Y-polarized signal, by a predetermined delay time &#x3c4;, relative to FAS in the X-polarized signal. The polarization multiplexing optical receiver includes a polarization splitter for splitting the received optical signal into two branches of polarized signals which are orthogonal to each other, a time difference detector for detecting a time difference of FASs between the two polarized signals, and a polarization identifying unit for identifying which of the two polarized signals is the X-polarized signal or Y-polarized signal.

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Kawasaki, Japan

Shota Mori