Abstract: Provided are a monitoring device, a monitoring method, and an optical transmission system which are adapted for an increase in the number of cores of a multi-core optical fiber transmission path and suitable for crosstalk monitoring. The monitoring device monitors a multi-core optical fiber transmission path having a plurality of use cores and at least one or more non-use cores, and comprises: an applying means for applying, at a start point of the multi-core optical fiber transmission path, dithering to signal light propagating in the use cores; a monitoring means for monitoring the power of the non-use cores at an input side of a relay in the multi-core optical fiber transmission path; and a separating means for separating a monitoring result from the monitoring means into power components from the plurality of use cores.

Abstract: An optical communication system includes a first terminal device configured to receive first data, wherein the first terminal device is configured to generate an optical waveform based on the received first data. The optical system further includes an optical communication path configured to receive the optical waveform from the first terminal device. The optical system further includes a second terminal device configured to receive the optical waveform from the optical communication path, wherein the second terminal device is configured to output second data based on the optical waveform. At least one of the first terminal device or the second terminal device includes a nonlinear waveform distortion compensation device. The nonlinear waveform compensation device is configured to correct nonlinear waveform distortion resulting from the optical waveform propagating along the optical communication path, and the nonlinear waveform compensation device includes at least one recursive intermediate layer.

Abstract: In optical amplifiers that use a multicore optical fiber, the absorption efficiency of excitation light in an optical amplification medium is low and the amplification efficiency of light intensity becomes lower in the cladding excitation method; therefore, an optical amplification apparatus according to the present invention includes an optical amplification medium, having a gain in a wavelength band of signal light, configured to receive the signal light; excitation light introduction means for introducing, into the optical amplification medium, excitation light to excite the optical amplification medium; and residual excitation light introduction means for introducing, into the optical amplification medium, residual excitation light output from the optical amplification medium, the residual excitation light having a wavelength component of the excitation light.

Abstract: It is difficult to flatten the gain profile of an optical amplifier without increasing the power consumption, the cost, and the size of the optical amplifier; therefore, a monitoring apparatus for optical amplifier according to an exemplary aspect of the invention includes an optical filtering means for receiving a monitor light beam of the optical amplifier and transmitting a filtered monitor light beam with a set range of wavelength band; a photoelectric conversion means for converting the filtered monitor light beam into a monitoring signal; and a spectrum information generating means for generating spectrum information based on the monitoring signal, the spectrum information including information on a spectrum profile of output of the optical amplifier.

Abstract: A symbol constellation generation apparatus (2000) acquires specification information (10) of the optical communication system (100). The symbol constellation generation apparatus (2000) uses a first prediction model (50) to generate noise characteristics information (20) based on the specification information (10). The symbol constellation generation apparatus (2000) uses a second prediction model (60) to generate symbol constellation (30) suited to the optical communication system having the noise characteristics represented by the noise characteristics information (20).

Abstract: A pumping light source outputs pumping lights. A pumping light source outputs a pumping light. Optical multiplexers couple the pumping lights to a plurality of cores. The optical multiplexer couples the pumping light to the clad. A pumping light source drive unit drives a pumping light source. A pumping light source drive unit drives a pumping light source. A monitoring unit outputs a monitoring signal indicating a monitoring result of the number of wavelengths used in each of optical signals amplified by the plurality of the cores. The control unit controls the power of the pumping lights based on the monitoring signal. The control unit controls the power of each of the pumping lights in accordance with the number of wavelengths used in each of the optical signals and controls the power of the pumping light so that signal qualities of the optical signals fall within a prescribed range.

Abstract: 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.

Abstract: An optical amplifier that amplifies an incident WDM signal and includes cores having an amplification medium, the optical amplifier includes: a wavelength demultiplexer configured to demultiplex the incident WDM signal into wavelength bands and introducing the demultiplexed WDM signals into the cores separately; a wavelength multiplexer configured to multiplex amplified optical signals propagated through the cores and outputting the multiplexed signal; and an wavelength demultiplexing controller configured to monitor an amplification rate of a specific wavelength band of an amplified WDM signal or a scale associated with an amplification rate of a specific wavelength band, demultiplexing, from the incident WDM signal, an optical signal of a wavelength band having relatively-small optical amplification efficiency according to a monitoring result, and controlling demultiplexing performed by the wavelength demultiplexer in such a way as to amplify, with a relatively-large amplification rate, the optical signal o

Abstract: This disclosure relates to a signal processing system for an optical communication system including an optical transmitter and an optical receiver. The signal processing system is configured to: identify a distortion of input signals from an optical receiver in an unsupervised manner to output distortion parameters indicating the distortion identified; and utilize the outputted distortion parameters to modify signal inputted to an optical transmitter.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In order to solve the problem that the power consumption of optical amplifiers is not optimized over the life time of a network whose capacity in use varies, an optical amplifier according to an exemplary aspect of the invention 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; monitoring means for monitoring the plurality of optical channels inputted into the gain medium and producing a monitoring result; a first light source configured to emit a first light beam to excite the cladding area; a second light source configured to emit a plurality of second light beams to excite each of the plurality of cores individually; and controlling means for making a decision as to whether each of the plurality of cores to transmit one of the plurality of optical channels based on the monitoring result, and controlling the firs

Abstract: 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.

Abstract: A submarine optical communication system control device (1) according to the present invention includes: a light intensity distribution determination device (2) configured to determine an optimum distribution of signal light intensity of each optical path for each allocated frequency; a light intensity distribution measuring device (3) configured to measure a light intensity distribution of an optical path after transmission through a submarine cable transmission line; an equalization setting calculation unit (4) 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 (5) 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.

Abstract: An optical transmitter using multiplexed optical signals increases in cost and in size in order to control an optical carrier frequency with high precision, therefore, an optical transmitter according to an exemplary aspect of the invention includes optical signal generating means for adding a first optical component to a first optical carrier and adding a second optical component to a second optical carrier; multiplexing means for multiplexing the first optical carrier and the second optical carrier to generate a multiplexed optical signal; monitoring means for monitoring the multiplexed optical signal to detect a monitor signal having a difference frequency between the first optical component and the second optical component; and controlling means for controlling a carrier frequency of at least one of the first optical carrier and the second optical carrier according to the monitor signal.

Abstract: In the optical transmission system to transmit optical signals using a plurality of adjacent paths, it is difficult to detect a delay difference between a plurality of paths and chromatic dispersion with a high degree of accuracy due to a crosstalk; therefore, a method for detecting optical signal information according to an exemplary aspect of the present invention includes generating a plurality of data signal sequences corresponding to a plurality of paths multiplexed spatially, each of the plurality of data signal sequences obtained by inserting periodically a training signal with a plurality of frequency components in a data signal, in the plurality of data signal sequences, the training signals respectively included in the data signal sequences to be propagated through adjacent paths at least having different frequency components from each other at the same timing, each of a plurality of the training signals included in one of the data signal sequences having the plurality of frequency components whose

Abstract: To improve the signal quality of the optical signal emitted by a reconfigurable transmitter after a reconfiguration event, an optical transmitter includes a modulator, a digital signal processor, and a controller. The modulator is for modulating light by a driving signal with a reconfigurable format. The digital signal processor is for processing digital data to be transmitted by using parameters in order to generate the driving signal. The controller is for controlling the digital signal processor changing the parameters so as to keep the driving signal stable before and after changing the reconfigurable format.

Abstract: It is impossible to compensate non-linearity in an optical transmitter during operations, therefore, an optical transmitter according to an exemplary aspect of the invention includes a selective addition means for adding a coefficient to digital data to be transmitted if the digital data being included in one of data intervals of predetermined number, the predetermined number being integer more than one, and for changing the coefficient with a period longer than the symbol period of the data transmitted by the optical transmitter; a data processing means for processing the digital data by using a parameter; a driving signal means for generating a driving signal from the digital data adjusted by the selective addition means and the data processing means; a modulating means for modulating light into lightwave signal by the driving signal; and a control means for receiving a monitor signal obtained by monitoring the lightwave signal having a frequency component determined by the period of changing the added coef