Abstract: Provided is a method for opening an optical communication path, in which one or more optical switches include a plurality of first ports and a plurality of second ports, and a management control device switches connection such that other first ports grouped with a transmission port connected first port of the one or more optical switches connected to a transmission port of the one subscriber device are sequentially connected to one second port to which a response request signal is input, transmits the response request signal to the one second port each time the connection is switched, specifies a reception port connected first port connected to a reception port of the one subscriber device in accordance with reception of a response signal in response to the response request signal, and sets a connection relation between the ports of the one or more optical switches such that an optical signal input to the transmission port connected first port reaches an optical transmission line to which a reception port of

Abstract: An aspect of the present invention includes: an authentication step of authenticating an optical terminal; a scheme setting step of setting a communication scheme to be used between the terminal and a connection destination terminal to which the terminal is connected; a wavelength setting step of setting a wavelength to be used between the terminal and the connection destination terminal; and a path setting step of setting an optical path to be used between the terminal and the connection destination terminal.

Abstract: Provided is an optical access system that performs communication using an optical signal on which a management control signal used for management and control is superimposed, the optical access system including: a subscriber device on a transmitting side that generates an optical signal by superimposing the management control signal on a main signal and transmits the generated optical signal; a management control unit that outputs a management control signal which is superimposed on the optical signal transmitted by the subscriber device on the transmitting side and which has a frequency band different from a frequency of the management control signal superimposed on the optical signal; and a control signal superimposing unit that superimposes the management control signal output from the management control unit on the optical signal.

Abstract: An optical line terminal includes a communication unit configured to communicate with a plurality of optical network units, and a control unit configured to dynamically change at least one of a time width of a specific period and a cycle of the specific period, the specific period being a period in which an authentication request signal is received from the new optical network unit via the communication unit.

Abstract: An aspect of the present invention is a control system required for optical communication, the control system including: a control unit that performs communication with a plurality of terminal devices using an optical signal, a control transceiver that performs conversion between an optical signal and an electrical signal, and a control optical switch that switches a connection destination of the control transceiver, in which the control unit switches the connection destination of the control transceiver by controlling an operation of the control optical switch, and the number of control optical switches is smaller than the number of terminal devices.

Abstract: The communication device includes: a reception unit that receives burst frame signals from a plurality of other communication devices respectively; and a control unit that changes a block length of a moving average filter in carrier phase synchronization so as to minimize a phase noise amount of the burst frame signals.

Abstract: An optical transmission apparatus includes an optical transmitter that generates an optical signal in an uplink direction by modulating output light of a laser that outputs light of a first frequency with a subcarrier on which transmission data is superimposed, a heterodyne detection unit that receives an optical signal in a downlink direction by heterodyne detection, a control unit that calculates a first intermediate frequency based on the frequency of the downlink signal received by the heterodyne detection and the first frequency of the laser, and controls the first frequency of the laser when there is a difference between the calculated first intermediate frequency and a reference second intermediate frequency by a threshold or more.

Abstract: An optical switch having a plurality of ports outputs an optical signal, which is input from one of the plurality of ports, from another port. A quality compensator perform quality compensation of the optical signal output from the optical switch, and input the quality-compensated optical signal to the optical switch. A controller selects, among the plurality of quality compensators, a quality compensator that performs quality compensation according to the degree of quality deterioration of the optical signal when the optical signal input from a predetermined port of the optical switch is transmitted through a transmission path. The controller controls the optical switch so that the optical signal, in which quality is compensated by the selected quality compensator through the optical signal input from the predetermined port being output to the selected quality compensator, is output from the port corresponding to a transmission destination of the optical signal.

Abstract: An optical communication system includes: an optical fiber including a plurality of cores; a first optical communication device provided with an optical transmission unit and an optical reception unit each connected to one end of one of the cores on an interface surface; and a second optical communication device provided with an optical transmission unit and an optical reception unit each connected to another end of any one of the cores on an interface surface, in which one of the connection ends of the first optical communication device and of the second optical communication device being in a line-symmetric positional relationship with respect to a vertical line to a horizontal plane of when the first optical communication device and the second optical communication device are installed on the horizontal plane such that the interface surfaces of the first optical communication device and the second optical communication device face a front.

Abstract: An optical transmission device which transmits an optical signal between a communication terminal device and a network, without converting the optical signal into an electric signal, the optical transmission device including: a plurality of multiplexing/demultiplexing units which input and output the optical signal to and from the communication terminal device connected to an own device; a plurality of wavelength multiplexing separation units which input and output the optical signal to and from a network connected to the own device; an upstream signal demultiplexing unit which outputs the optical signal in an upstream direction, which is output from the multiplexing/demultiplexing unit, to an electric processing unit that executes predetermined electric processing on the optical signal; and an upstream signal multiplexing unit which outputs the optical signal in the upstream direction subjected to the electric processing by the electric processing unit to the predetermined wavelength multiplexing separation

Abstract: An optical transmitter (3) tracks a moving body (1) and irradiates the moving body (1) with a laser beam (4). An optical receiver (5) is mounted on the moving body (1), receives the laser beam (4), and performs optical space communication with the optical transmitter (3). The optical transmitter (3) extends an irradiation range (6) of the laser beam (4) into an elliptical shape.

Abstract: A reception unit, in which a range of an electric band is in a range from ?Be to +Be and Be >B/2 is satisfied, receives signal light of a symbol rate B generated by optically modulating transmission data, performs digital coherent reception by interfering the received signal light with the local oscillation light generated by the local oscillation light source, converts the signal light into an electric digital signal, and output the digital signal, and a frequency offset compensation unit provided in a digital signal processing unit estimates a frequency offset amount generated in the digital signal in a range of ?B/2 or more and +B/2 or less in accordance with a frequency difference between the signal light and the local oscillation light, and perform frequency offset compensation for the digital signal on the basis of the estimated frequency offset amount to compensate the frequency offset amount in a range of ?B/2 or more and +B/2 or less and compensate so as to remain the frequency offset amount of an

Abstract: An optical transmission apparatus that transmits an optical signal between a communication terminal device and a network without converting the optical signal into an electrical signal includes: a plurality of multiplexing/demultiplexing units configured to receive and output optical signals from and to the communication terminal device connected to the optical transmission apparatus; a plurality of wavelength multiplexing/separating units configured to receive and output optical signals from and to the network connected to the optical transmission apparatus; and an optical distribution unit configured to output optical signals output from the multiplexing/demultiplexing units and subjected to predetermined electrical processing to a predetermined multiplexing/demultiplexing unit.

Abstract: An optical transmitter includes: a main signal generation unit that generates a main signal; a control signal generation unit that generates a control signal having a speed lower than a speed of the main signal; a wavelength-tunable driver that converts the control signal generated by the control signal generation unit into a signal for wavelength control; and a wavelength-tunable transmitter that generates a modulated optical signal on the basis of the main signal and the signal for wavelength control.

Abstract: An optical communication system includes a communication control unit configured to control opening of an optical path between any of a plurality of first communication devices and any of a plurality of second communication devices, and an optical multiplexing/demultiplexing unit configured to multiplex/demultiplex signal light of a control signal transferred between each of the plurality of first communication devices and the communication control unit after the optical path is opened, and the communication control unit controls reception timings of an uplink control signal transmitted from each of the plurality of first communication devices to the communication control unit to be different from each other by permitting each of the plurality of first communication devices to transmit the uplink control signal on the basis of each round trip time of signal light reciprocating between the communication control unit and each of the plurality of first communication devices.

Abstract: A code error rate estimation device included in an optical transmission system using a direct detection receiver, the code error rate estimation device including: a transmission path model creation unit that creates a physical model of a transmission path for each candidate path for performing communication between user devices that perform communication; a propagation waveform calculation unit that generates an electric field signal waveform to be output from a transmitter assumed in the physical model of the transmission path and generates a reception signal waveform at the time of direct detection by using linear fiber propagation simulation; a nonlinear noise calculation unit that calculates nonlinear noise light intensity of light on the basis of the physical model of the transmission path; a noise intensity conversion unit that converts the calculated nonlinear noise light intensity of the light into noise in an electrical stage; a reception signal waveform calculation unit that calculates a Gaussian di

Abstract: A slave station device including: a superposition unit that is capable of superposing a main signal and a master station control signal by an electrical domain superposition method in which the main signal and the master station control signal for controlling a master station device connected to the slave station device are converted into an optical signal after multiplexing and an optical domain superposition method in which the main signal is modulated into an optical signal and then optically modulated by the master station control signal, and superposes the main signal and the master station control signal by any one of the electrical domain superposition method and the optical domain superposition method; and a control unit that controls the superposition method by the superposition unit on the basis of a slave station control signal indicating the superposition method received from the master station device.

Abstract: A signal transfer device includes an optical interface unit, first and second interface units, and first and second conversion units. The optical interface unit performs processing of converting a received optical signal into an electric signal to generate a reception signal, and performs processing of converting a transmission signal from an electric signal to an optical signal to transmit the converted optical signal. The first conversion unit converts the reception signal generated by the optical interface unit into a signal of a first protocol, and transmits the signal from the first interface unit. The second conversion unit converts a signal of a second protocol received by the second interface unit into a transmission signal to be transmitted by an optical signal, and outputs the converted transmission signal to the optical interface unit. Each of the first and second interface units is attachable to and detachable from the signal transfer device.

Abstract: A transmitting apparatus includes a direct modulation laser, a branching unit, a first signal generation unit, a second signal generation unit, and a polarized wave multiplexing unit. The branching unit branches continuous phase frequency shift keying signal light having been generated by the direct modulation laser by applying a first modulation signal into first branch light and second branch light. The first signal generation unit generates first polarized wave signal light obtained by removing an intensity modulation component having been generated by the direct modulation laser by applying the first modulation signal from the first branch light. The second signal generation unit generates second polarized wave signal light obtained by removing the intensity modulation component from the second branch light and adding an intensity modulation component to the second branch light by applying a second modulation signal, the second polarized wave being orthogonal to the first polarized wave.

Abstract: Provided is an optical transmission device including: a modulation signal generation unit that generates an intensity modulation signal and a continuous phase frequency shift keying (CPFSK) signal; a light source that outputs a signal modulated by the CPFSK signal; and an intensity modulation unit that performs intensity modulation for canceling an intensity modulation component generated by modulation by the CPFSK signal, and intensity modulation by the intensity modulation signal, on the signal output from the light source.