Abstract: An optical modulator includes an optical waveguide, a first slab and a second slab. The optical waveguide is formed by filling polymer in a slot portion formed between a first rail and a second rail disposed in parallel to the first rail. The first slab includes a first partial slab electrically connected to a first electrode and a second partial slab that electrically connects the first rail and the first partial slab. In the first slab, a thickness dimension of the second partial slab is set small compared with that of the first rail. The second slab includes a third partial slab electrically connected to a second electrode and a fourth partial slab that electrically connects the second rail and the third partial slab. In the second slab, a thickness dimension of the fourth partial slab is set small compared with that of the second rail.

Abstract: A disclosed electronic device includes a graphite laminate having a plurality of layers laminated in a first direction, each layer containing graphite, where the graphite laminate has a portion in a stepwise form in which edges of the plurality of layers are offset from each other.

Abstract: An optical communications device includes a support, a plate-shaped member, and an optical cable. The plate-shaped member is supported in a curved state on the support. The plate-shaped member is a flexible printed circuit including a flexible substrate and a metallic pattern formed on the flexible substrate. The optical cable is provided along a curved surface of the plate-shaped member on the support.

Abstract: An optical communications device includes a support, a plate-shaped member, and an optical cable. The plate-shaped member is supported in a curved state on the support. The plate-shaped member is a flexible printed circuit including a flexible substrate and a metallic pattern formed on the flexible substrate. The optical cable is provided along a curved surface of the plate-shaped member on the support.

Abstract: A disclosed electronic device includes a graphite laminate having a plurality of layers laminated in a first direction, each layer containing graphite, where the graphite laminate has a portion in a stepwise form in which edges of the plurality of layers are offset from each other.

Abstract: An optical adapter includes: a housing having a plurality of openings on each of opposite end surfaces thereof; a plurality of ports formed in parallel with each other inside the housing and each extending to form one of the openings on each of the opposite ends surfaces, an optical connector being inserted into each of the openings; and a shutter part installed at each of the ports such that when the optical connector is inserted into an opening of one end of the port, the shutter part leans back to a retreat position that passes light emitted from the optical connector inserted into an opening of another end of the port, when the optical connector is pulled out of the opening of the one end of the port, the shutter part is raised up from the retreat position to a blocking position that blocks the emitted light.

Abstract: An optical adapter includes: a housing having a plurality of openings on each of opposite end surfaces thereof; a plurality of ports formed in parallel with each other inside the housing and each extending to form one of the openings on each of the opposite ends surfaces, an optical connector being inserted into each of the openings; and a shutter part installed at each of the ports such that when the optical connector is inserted into an opening of one end of the port, the shutter part leans back to a retreat position that passes light emitted from the optical connector inserted into an opening of another end of the port, when the optical connector is pulled out of the opening of the one end of the port, the shutter part is raised up from the retreat position to a blocking position that blocks the emitted light.

Abstract: An optical amplifier includes a photodiode configured to measure power of an output light; a converter configured to convert the power of the output light into a voltage signal; and a processor configured to determine whether a difference between a level of the voltage signal and a predetermined potential is equal to or higher than a first predetermined value, change power of excitation light so that the level of the voltage signal approaches the predetermined value, when it is determined that the difference is equal to or higher than the first predetermined value, determine whether the power of the excitation light is equal to or higher than a second predetermined value, after the power of the excitation light is changed, and reduce the power of the excitation light, when it is determined that the power of the excitation light is equal to or higher than the second predetermined value.

Abstract: An arrayed optical amplifier includes: at least one first amplifier including a first excitation light source controlled to a first temperature; at least one second amplifier including a second excitation light source controlled to a second temperature different from the first temperature; and a control circuit coupled to the at least one first amplifier and the at least one second amplifiers.

Abstract: An amplifying device includes a light source configured to output excitation light, a depolarizer configured to change a degree of polarization of the excitation light in accordance with a setting, an amplifier configured to execute Raman amplification so as to amplify a polarized multiplexed optical signal by the excitation light of which the degree of the polarization has been changed by the depolarizer, a measurer configured to measure the power of a plurality of polarized light components multiplexed into the polarized multiplexed optical signal subjected to the Raman amplification and amplified by the excitation light, and an adjuster configured to calculate differences between the power of the plurality of polarized light components and adjust the setting of the depolarizer so as to reduce the differences between the power of the plurality of polarized light components.

Abstract: An arrayed optical amplifier includes: at least one first amplifier including a first excitation light source controlled to a first temperature; at least one second amplifier including a second excitation light source controlled to a second temperature different from the first temperature; and a control circuit coupled to the at least one first amplifier and the at least one second amplifiers.

Abstract: An amplifying device includes a light source configured to output excitation light, a depolarizer configured to change a degree of polarization of the excitation light in accordance with a setting, an amplifier configured to execute Raman amplification so as to amplify a polarized multiplexed optical signal by the excitation light of which the degree of the polarization has been changed by the depolarizer, a measurer configured to measure the power of a plurality of polarized light components multiplexed into the polarized multiplexed optical signal subjected to the Raman amplification and amplified by the excitation light, and an adjuster configured to calculate differences between the power of the plurality of polarized light components and adjust the setting of the depolarizer so as to reduce the differences between the power of the plurality of polarized light components.

Abstract: An OCM monitors a plurality of SW ports each receiving an optical signal by switching the SW ports. The OCM includes a PD, a control circuit, and an arithmetic circuit. The PD detects an optical power level on wavelengths spaced at predetermined intervals in each of the SW ports to be monitored. The control circuit determines, in each of the SW ports, whether arithmetic processing using a waveform estimated from the optical power level is executed, depending on presence or absence of a change in the optical power level detected by the PD. The arithmetic circuit performs the arithmetic processing by using the waveform when the control circuit determines execution of the arithmetic processing.

Abstract: A tunable dispersion compensation device includes a plurality of tunable dispersion compensators coupled in series, a controller configured to control an amount of chromatic dispersion to be set in each of the plurality of tunable dispersion compensators, and a table including a correspondence relationship between an amount of chromatic dispersion and a wavelength band, for each of the plurality of tunable dispersion compensators, wherein the controller decides an amount of chromatic dispersion to be set in each of the plurality of tunable dispersion compensators, based on a total amount of chromatic dispersion desired for the plurality of tunable dispersion compensators and the correspondence relationship included in the table so that a difference between bandwidths of a first tunable dispersion compensator having the widest wavelength band and a second tunable dispersion compensator having the narrowest wavelength band, among the plurality of tunable dispersion compensators, is within a given range.

Abstract: An optical transmission device includes an extractor that extracts respective optical signals from optical signals multiplexed from a plurality of optical signals of different wavelengths, a detector that detects wavelengths of the extracted respective optical signals, a storage that stores the wavelengths of the detected respective optical signals, and a processor that is operative to derive trends in wavelength variation of the respective optical signals based on the detected respective optical signals and the respective optical signals stored in the storage, and determines that either one or both of the extractor and the detector cause the wavelengths to be varied when the trends in wavelength variation of two or more wavelengths are the same.

Abstract: An OCM monitors a plurality of SW ports each receiving an optical signal by switching the SW ports. The OCM includes a PD, a control circuit, and an arithmetic circuit. The PD detects an optical power level on wavelengths spaced at predetermined intervals in each of the SW ports to be monitored. The control circuit determines, in each of the SW ports, whether arithmetic processing using a waveform estimated from the optical power level is executed, depending on presence or absence of a change in the optical power level detected by the PD. The arithmetic circuit performs the arithmetic processing by using the waveform when the control circuit determines execution of the arithmetic processing.

Abstract: There is provided an optical transmission receiver includes an optical switch configured to switch between optical transmission channels, the optical transmission channels being gradually switched from one to the other, an optical amplifier configured to amplify a light propagating in the other of the optical transmission channels which is in a state subsequent to switching, and a switching speed controller configured to control a switching speed of the optical switch based on a level of the light amplified by the optical amplifier.

Abstract: An optical transmission device includes: a variable dispersion compensator to give chromatic dispersion and output an input light, a branching unit to branch the light output from the variable dispersion compensator to a first part and a second part, a reproduction unit to reproduce an electric signal from the first part of the input light, a monitor unit to perform reproducing processing on the electric signal from the second part of the input light, control the variable dispersion compensator based on a result of the reproducing processing, and has a sensitivity to a variation of the chromatic dispersion which is higher than the sensitivity to the variation of the chromatic dispersion of the reproduction unit.

Abstract: An optical transmitter includes an optical isolator that includes a Faraday rotator transmitting light output from a light source, and has a first state in which the light is transmitted through the optical isolator when a first magnetic field is applied to the Faraday rotator, and a second state in which the amount of the light transmitted through the optical isolator is less than that in the first state when a second magnetic field different from the first magnetic field is applied to the Faraday rotator; a junction to which an optical transmission medium into which the light output from the optical isolator is input is connected; a magnetic-field generator that selectively applies the first magnetic field or the second magnetic field to the Faraday rotator; and a switching unit that switches the magnetic-field generator to the second state when the optical transmission medium is not connected to the junction.

Abstract: A dispersion compensating apparatus includes a tunable dispersion compensator that dispersion-compensates an optical signal using a group delay property that is asymmetrical in bands outside an effective band; a set device that sets a dispersion compensation amount in the tunable dispersion compensator; and a shifter that shifts a central frequency of the effective band of the tunable dispersion compensator, based on the dispersion compensation amount set by the set device.