Nec Corporation

Shigeyuki Yanagimachi

Emmanuel Le Taillandier De Gabory

Keiichi Matsumoto

Shigeru Nakamura

Hitoshi Takeshita

Takashi Yoshikawa

Youichi Hidaka

Shinsuke Fujisawa

Junichi Higuchi

Jun Suzuki

Akio Tajima

Hidemi Noguchi

Kazuhiko Kurata

Yohei Hasegawa

Junichi Sasaki

Kiyo Ishii

Syu Namiki

In a network using MCF, in order to provide a technology which enables a standby system path to be easily constructed, this optical network includes: an active system path which is connected by means of a first multi-core optical fiber, and is a path between a transmission node that transmits an optical signal and a reception node that receives the optical signal; and the standby system path which is composed by means of a plurality of second multi-core optical fibers, which are different from the first multi-core optical fiber, and is a path switchable from the active system path between the transmission node and the reception node, wherein cores, which are switching destinations of the plurality of cores of the first multi-core optical fiber, are disposed at a plurality of respective unused cores of the second multi-core optical fibers.

Optical network, network management device, and network management method

The optical amplifier, which amplifies wavelength multiplexed signal light, comprises: a multi-core optical fiber which includes cladding and a first core and a second core disposed in the cladding, and which is doped with rare-earth ions; an excitation light source for supplying excitation light to the cladding of the multi-core optical fiber; and a wavelength demultiplexing means for separating the wavelength bands of the wavelength multiplexed signal light that has propagated through the first core. The signal light of a relatively long wavelength band among a plurality of wavelength bands separated by the wavelength demultiplexing means is caused to propagate through the second core, and is then multiplexed with the signal light of a relatively short wavelength band among the plurality of wavelength bands separated by the wavelength demultiplexing means, and the resultant multiplexed signal light is output.

Optical amplifier, optical amplifier equalizing method, and transmission system

Provided is a communication device that can deliver an improvement in the communication capacity of communication infrastructure with the quality of communication taken into consideration. A communication device includes an acquiring unit configured to acquire quality information of a communication line extending from a first communication device to a second communication device and including an optical communication line, an estimating unit configured to estimate the quality of communication of the second communication device and determine the required quality of communication of the second communication device based on the quality information, and a controlling unit configured to perform control on communication channels in the optical communication line so that the quality of communication satisfies the required quality of communication.

Communication device, communication controlling method, non-transitory computer-readable medium, and optical communication system

It is difficult to construct an optical fiber transmission system enabling relay optical amplification using a coupled multi-core optical fiber as an optical transmission path; therefore, an optical amplification device includes first optical spatial layout converting means for converting a spatial layout of a plurality of optical signal beams propagating through each of a plurality of cores, from a coupled state in which optical signal beams interfere between a plurality of cores to a non-coupled state in which optical signal beam interference is reduced between a plurality of cores; optical amplifying means for amplifying, in the non-coupled state, the plurality of optical signal beams with the non-coupled state and generating a plurality of amplified optical signal beams; and second optical spatial layout converting means for converting a spatial layout of the plurality of amplified optical signal beams from the non-coupled state to the coupled state.

Optical amplification device, optical transmission system, and optical amplification method

Provided are a low-cost and low power-consumption optical fiber amplifier, an optical fiber amplifier control method, and a transmission system. The optical fiber amplifier comprises: an optical fiber to which pumping light is supplied and which amplifies an optical signal, the optical fiber including a plurality of cores in a cladding; a light source which outputs the pumping light; a combining means which supplies the pumping light from the light source to the cladding of the optical fiber and causes the pumping light to be combined with the optical signal; a collect means which collects, without collecting the signal light, pumping light among the supplied pumping light that has not been absorbed by the optical fiber; a monitor means which monitors residual pumping light that has passed through the optical fiber and collected by the collect means; and a control means which controls the state of the pumping light.

Optical fiber amplifier, optical fiber amplifier control method, and transmission system

An optical amplifier uses, in a gain medium, a multicore optical fiber having a plurality of cores, and comprises: an input-light power monitor that monitors the optical power of input light to the plurality of cores of the multicore optical fiber; an output-light power monitor that monitors the optical power of medium-passed output light from the plurality of cores that has passed through the multicore optical fiber; a crosstalk monitor that monitors the amount of inter-core crosstalk among the plurality of cores; and a controller that controls the pump-light power of pump light superimposed on the input light to the plurality of cores on the basis of the monitored optical power of input light, the monitored optical power of output light, and the monitored amount of inter-core crosstalk.

Optical amplifier, and control method therefor

High-speed control of disaggregated network systems is implemented. A control device includes a main memory and an interface. The main memory shares management information contained in memory spaces possessed by a plurality of respective component devices connected and stores the management information as integrated management information. When the management information is to be updated, the interface transmits an update signal for updating the management information to the component devices and receives a response signal to the update signal from the component devices.

Control device, control system, network system, control method, and computer-readable medium

An optical network management device () which assigns a path from a transmitting node to a receiving node in an optical network system including a multi-core optical fiber, includes at least one processor, the processor being configured to carry out: a core extraction process of extracting a core constituting the path; and a path assignment process of selecting, in accordance with an attribute of the path, a wavelength to which the path is to be assigned, the multi-core optical fiber having an optical amplifier attached thereto, the optical amplifier having an amplification gain that is larger in a first wavelength region than in a second wavelength region, the path assignment process including preferentially assigning, to the first wavelength region, the path having a specific attribute.

Optical network management device, optical network system, optical network management method, and optical network management program

A multicore optical fiber amplifier according to an exemplary aspect of the present invention includes a multicore optical fiber amplification medium including, in a clad, a plurality of cores doped with a rare earth element; signal light introduction means for introducing, into each of the plurality of cores, signal light with a wavelength included in a gain band of the multicore optical fiber amplification medium; excitation light introduction means for introducing, into the clad, excitation light for exciting the multicore optical fiber amplification medium; and control light introduction means for introducing control light into each of the plurality of cores, wherein the control light introduction means introduces the control light into a non-signal core into which the signal light is not being introduced, among the plurality of cores, only when the excitation light is being introduced.

Multicore optical fiber amplifier and optical amplification method using multicore optical fiber amplification medium

It is necessary to reduce the power consumption of a plurality of optical amplifiers when there is a difference in the required pumping power between the plurality of optical amplifiers; therefore, an optical amplifying apparatus according to an exemplary aspect of the invention includes a plurality of optical amplifying means for amplifying a plurality of optical signals, each of the plurality of optical amplifying means including a gain medium; a plurality of laser light generating means for generating a plurality of laser beams; at least one optical coupling means for coupling the plurality of laser beams variably in accordance with a coupling factor and outputting a plurality of excitation light beams, each of the plurality of excitation light beams exciting the gain medium; and controlling means for controlling the coupling factor and an output power of each of the plurality of laser light generating means.

Optical amplifying apparatus and method of amplifying optical signal

To solve the problem that the power consumption of optical amplifiers is not optimized over the life time of an amplifier, the optical amplifier includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores, a monitor that monitors the temperature of the optical amplifier and producing a monitoring result, a first light source that emits a first light beam to excite the cladding area, a second light source that emits a plurality of second light beams to excite each of the plurality of cores individually, and a controller that controls the first light source and the second light source based on the produced monitoring result.

Optical amplifier and control method therefor

This optical path setting device comprises: a transmission characteristic calculating means for calculating an inter-endpoint transmission characteristic that is a characteristic for transmission between endpoints of an optical path accommodating traffic in a plurality of optical communication systems; a required wavelength bandwidth determining means for determining a required wavelength bandwidth that is a wavelength bandwidth meeting an arrival performance of the optical path on the basis of the inter-endpoint transmission characteristic; and an accommodating wavelength band determining means for determining, as an accommodating wavelength band for accommodating the optical path, a common wavelength band that is a wavelength band where an optical path having the required wavelength bandwidth can be allocated, and that is common to the plurality of optical communication systems.

Optical path setting device, optical communication system, and optical path setting method

A submarine optical communication system control device () according to the present invention includes: a light intensity distribution determination device () configured to determine an optimum distribution of signal light intensity of each optical path for each allocated frequency; a light intensity distribution measuring device () configured to measure a light intensity distribution of an optical path after transmission through a submarine cable transmission line; an equalization setting calculation unit () configured to calculate a gain equalization setting for compensating for the difference between an optimum distribution in the light intensity distribution determination device and a measured distribution in the light intensity distribution measuring device; and a variable gain equalizer () configured to compensate for a light intensity distribution of an optical path to the optimum distribution, based on a gain equalization setting in the equalization setting calculation unit.

Submarine optical communication control device, control method, and non-transitory computer-readable medium

A packet communication device autonomously selects an appropriate operation mode according to a connection environment to an external device before a service of the device is started. When the device is connected to the external buses, connection interface units notify an external device discrimination unit of connection of the device. The external device discrimination unit issues a polling packet to the connected device, discriminates the connected external device on the basis of the response packet, and notifies an operation mode switching unit. The operation mode switching unit selects an operation mode conforming to a connection environment of the packet communication device to the external device and switches the operation mode of the device to the mode. The selection of the operation modes is completed before the entire device or a portion of the device which is influenced by the selection of the operation mode starts a service to the external device to which the packet communication device is connected.

Packet communication device which selects an appropriate operation mode

An optical backplane connector with a board removable (being possible to insert and remove) therein in the direction perpendicular to the backplane plate surface is arranged on a backplane having optical transmission paths. The optical backplane connector accommodates a photoelectric conversion module in such a manner the incident and exit light are perpendicular to the backplane and a transparent board with a photoelectric conversion element mounted thereon is perpendicular to the board and parallel to the backplane. The conduction between the electric contacts of the photoelectric conversion module and the inner electric contacts of the optical backplane connector is held by mechanical contact. At the end portion of the optical transmission path on the backplane, an optical connector having a 45' mirror and guide pins is mounted. The positioning operation is achieved by fitting the guide pins of the optical connector with the guide holes of the photoelectric conversion module.

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Tokyo, Japan

Shigeyuki Yanagimachi