Abstract: An optical transmission path monitoring device according to the present disclosure includes a monitoring light generation circuit configured to generate first monitoring light, and send the first monitoring light to an optical transmission path, a time synchronization circuit configured to perform time synchronization with an opposite monitoring device connected to an opposite side of the optical transmission path, a light reception circuit configured to receive first returned light acquired by turning back the first monitoring light in a turnback circuit inserted in the optical transmission path, and second returned light acquired by multiple turning back, in the turnback circuit, second monitoring light sent by the opposite monitoring device, and a time control circuit configured to control a sending time of the first monitoring light by use of positional information of the turnback circuit.

Abstract: In order to avoid the phenomenon of communication being impeded and signals transmitted by the plurality of slave devices overlapping, a communication system according to the present invention has the first master device transmits a first pulsed light to the first transmission path and receives a return light of the first pulsed light from the second transmission path; each of the slave devices modulates the first pulsed light, and outputs the modulated first pulsed light as the return light of the first pulsed light; and the width of the first pulsed light is narrower than double the shortest distance from among the transmission distance between the slave device outputting the return light and the transmission distance between the first master device and the slave device outputting the return light.

Abstract: Provided are an optical transmission line monitoring apparatus, an optical transmission line monitoring system, and an optical transmission line monitoring method capable of monitoring a plurality of optical transmission lines in parallel. A monitoring light output unit outputs monitoring lights with different frequencies to optical transmission lines. A local oscillation light source outputs a local oscillation light. An interference unit, to which return lights corresponding to the monitoring lights are input, configured to output an output light generated by interference between input lights and the local oscillation light. A conversion unit converts the output light into an electrical signal. A signal processing unit extracts, from the electrical signal, an intermediate-frequency signal based on each of the monitoring lights, and generates monitoring results of the optical transmission lines from the intermediate-frequency signal.

Abstract: According to one example embodiment, a light-transmission-path-spectrum measurement device includes: a wavelength varying OTDR measurement unit that varies and generates a wavelength of measurement light to be transmitted to a first light transmission path, and also measures return light acquired from the measurement light being returned, by a repeater connected to the first light transmission path, via a second light transmission path connected to the repeater; an optical signal multiplexing unit that selects the wavelength of the measurement light being generated by the wavelength varying OTDR measurement unit, and outputs the selected wavelength to the first light transmission path; a control unit that controls the wavelength of the measurement light being generated by the wavelength varying OTDR measurement unit and the wavelength of the measurement light being selected by the optical signal multiplexing unit; and a measurement data processing unit.

Abstract: Provided are an optical transmission line monitoring apparatus, an optical transmission line monitoring system, and an optical transmission line monitoring method capable of monitoring a plurality of optical transmission lines in parallel. A monitoring light output unit outputs monitoring lights with different frequencies to optical transmission lines. A local oscillation light source outputs a local oscillation light. An interference unit, to which return lights corresponding to the monitoring lights are input, configured to output an output light generated by interference between input lights and the local oscillation light. A conversion unit converts the output light into an electrical signal. A signal processing unit extracts, from the electrical signal, an intermediate-frequency signal based on each of the monitoring lights, and generates monitoring results of the optical transmission lines from the intermediate-frequency signal.

Abstract: The optical relay is a C+L-band relay which is inserted between a first transmission path fiber and a second transmission path fiber, and comprises: a first optical fiber amplification unit which is inserted in a first line and amplifies one of a C-band signal or an L-band signal; a second optical fiber amplification unit which is inserted in a second line and amplifies one of the C-band signal or the L-band signal; and an inserting means which inserts some or all of the wavelengths of light output from the first optical fiber amplification unit into the second optical fiber amplification unit, or which inserts some or all of the wavelengths of light output from the second optical fiber amplification unit into the first optical fiber amplification unit.

Abstract: Aspects of the present disclosure describe systems, methods and structures including high-density submarine/undersea reconfigurable optical add/drop multiplexers (ROADM) having remote wavelength selective switch (WSS) redundancy.

Abstract: A management device managements an optical transmission system provided with a transmission path in which each transmission route between first and second optical transmitting/receiving devices has a different transmission path length. The management device includes collecting unit that registers route delay information indicating a transmission delay time for each of the transmission routes, and collects a measurement delay time being a transmission delay time of the transmission path being measured by the first optical transmitting/receiving device, and identifying unit that identifies the transmission route corresponding to the measurement delay time, based on the route delay information and the measurement delay time.

Abstract: Aspects of the present disclosure describe systems, methods and structures including high-density submarine/undersea reconfigurable optical add/drop multiplexers (ROADM) having remote wavelength selective switch (WSS) redundancy.

Abstract: Aspects of the present disclosure describe systems, methods and structures including high-density submarine/undersea reconfigurable optical add/drop multiplexers (ROADM) having remote wavelength selective switch (WSS) redundancy.

Abstract: To enable the transmission and reception of a super-channel optical signal to continue maintaining the possible transmission capacity without providing a redundant configuration in advance even though a failure occurs in a subcarrier, an optical transmitter 10 of the present invention includes a splitting means 20 for splitting an inputted client signal so as to make frequency efficiency in optical modulation means optimized; optical modulation means 31 to 3N for modulating one of subcarriers having mutually different wavelengths with the client signal output; a multiplexing means 40 for multiplexing the modulated signals and outputting a super-channel optical signal; and a control means 50, in a state where a failure occurs in one of the subcarriers, for making a split client signal output to modulation means corresponding to a subcarrier having no failure and applying a modulation method with a higher frequency efficiency to at least one of the modulation means.

Abstract: The optical relay is a C+L-band relay which is inserted between a first transmission path fiber and a second transmission path fiber, and comprises: a first optical fiber amplification unit which is inserted in a first line and amplifies one of a C-band signal or an L-band signal; a second optical fiber amplification unit which is inserted in a second line and amplifies one of the C-band signal or the L-band signal; and an inserting means which inserts some or all of the wavelengths of light output from the first optical fiber amplification unit into the second optical fiber amplification unit, or which inserts some or all of the wavelengths of light output from the second optical fiber amplification unit into the first optical fiber amplification unit.

Abstract: In order to provide a configuration for suppressing deterioration in the transmission quality of a signal light due to a nonlinear phenomenon in an optical fiber, a polarization dispersion adder is provided with: a polarization rotation unit which, with respect to each pulse of signal light generated by modulating a light carrier, rotates and outputs the polarization of the pulse during a period from a pulse rise start time (T0) to a pulse fall completion time (T1); and a delay addition unit which adds a delay of an amount corresponding to the rotation amount of the polarization added by the polarization rotation unit to the pulse outputted from the polarization rotation unit.

Abstract: To enable the transmission and reception of a super-channel optical signal to continue maintaining the possible transmission capacity without providing a redundant configuration in advance even though a failure occurs in a subcarrier, an optical transmitter 10 of the present invention includes a splitting means 20 for splitting an inputted client signal so as to make frequency efficiency in optical modulation means optimized; optical modulation means 31 to 3N for modulating one of subcarriers having mutually different wavelengths with the client signal output; a multiplexing means 40 for multiplexing the modulated signals and outputting a super-channel optical signal; and a control means 50, in a state where a failure occurs in one of the subcarriers, for making a split client signal output to modulation means corresponding to a subcarrier having no failure and applying a modulation method with a higher frequency efficiency to at least one of the modulation means.

Abstract: In order to provide a configuration for suppressing deterioration in the transmission quality of a signal light due to a nonlinear phenomenon in an optical fiber, a polarization dispersion adder is provided with: a polarization rotation unit which, with respect to each pulse of signal light generated by modulating a light carrier, rotates and outputs the polarization of the pulse during a period from a pulse rise start time (T0) to a pulse fall completion time (T1); and a delay addition unit which adds a delay of an amount corresponding to the rotation amount of the polarization added by the polarization rotation unit to the pulse outputted from the polarization rotation unit.

Abstract: An antenna coil may include a first coil portion wound with coil wire; a second coil portion wound with coil wire and intersecting with the first coil portion; and a case having a coil receiving portion receiving the first coil portion and the second coil portion, in which the first coil portion and the second coil portion are disposed so that extending directions of the respective coil portions are directed in diagonals direction of the coil receiving portion.

Abstract: In a transmission path monitoring system, a first add section adds a first add signal to a first wavelength division multiplexing signal. A first drop section separates a first drop signal from the first wavelength division multiplexing signal. A first loopback section transfers a monitor signal on a first drop optical transmission path onto a second add optical transmission path. A second add section adds a second add signal to a second wavelength division multiple signal. A second drop section separates a second drop signal from the second wavelength division multiplexing signal. A first communication section transmits the first add signal and the monitor signal and receive the second drop signal and the monitor signal.

Abstract: A coil part used in a antenna coil has a cross shape core that includes: a first winding frame part extending a first direction and being provided with a coil, and a second winding frame part extending a direction crossing the first direction and being provided with a coil. A first core including the first winding frame part is interlocked with a second core 20b including the second winding frame part.

Abstract: In a transmission path monitoring system, a first add section adds a first add signal to a first wavelength division multiplexing signal. A first drop section separates a first drop signal from the first wavelength division multiplexing signal. A first loopback section transfers a monitor signal on a first drop optical transmission path onto a second add optical transmission path. A second add section adds a second add signal to a second wavelength division multiple signal. A second drop section separates a second drop signal from the second wavelength division multiplexing signal. A first communication section transmits the first add signal and the monitor signal and receive the second drop signal and the monitor signal.

Abstract: The invention provides a coil part used for an antenna coil that improves the production rate and enhances its sensitivity. A coil part used in a antenna coil has a cross shape core that includes: a first winding frame part extending a first direction and being provided with a coil, and a second winding frame part extending a direction crossing the first direction and being provided with a coil. A first core including the first winding frame part is interlocked with a second core including the second winding frame part.