Abstract: An in-vehicle communication system includes: an optical coupler; a first in-vehicle device group composed of a plurality of in-vehicle devices connected to a first end of the optical coupler; and a second in-vehicle device group composed of a plurality of in-vehicle devices connected to a second end of the optical coupler. The in-vehicle devices in the first in-vehicle device group are communicable with the in-vehicle devices in the second in-vehicle device group via a common transmission path in the optical coupler. The in-vehicle devices in the second in-vehicle device group are communicable with the in-vehicle devices in the first in-vehicle device group via a common transmission path in the optical coupler.

Abstract: An on-board communication system includes an optical coupler that includes multiple optical transmission lines, and multiple on-board devices that are capable of communicating with each other with the optical coupler interposed therebetween.

Abstract: A vehicle wiring system includes a plurality of functional units to be mounted in a vehicle, an optical transmission line that is wired between the functional units and configured to transmit an optical signal of the functional units, an optical coupler that is disposed in a partial section of the optical transmission line and constitutes a part of the optical transmission line, and a structural member that constitutes a part of the vehicle and is at least partially transparent. The optical coupler has an optical waveguide that passes through the structural member.

Abstract: A vehicle wiring system includes a plurality of functional units to be mounted in a vehicle, an optical transmission line that is wired between the functional units and configured to transmit an optical signal of the functional units, an electric wire harness that is provided, in a partial section of the optical transmission line, together with the optical transmission line in a state of being integrated with the optical transmission line, and an optical coupler that is disposed in a portion of the optical transmission line other than the section and constitutes a part of the optical transmission line.

Abstract: An on-board communication system includes an optical coupler that includes multiple optical transmission lines, and multiple on-board devices that are capable of communicating with each other with the optical coupler interposed therebetween.

Abstract: A wavelength tunable light source includes a wavelength tunable laser device and a control device. The wavelength tunable laser device includes: M laser diodes configured to generate laser oscillation to output beams; a multiplexer/demultiplexer configured to multiplex the beams output from the M laser diodes to bifurcate the beams for output; a first semiconductor optical amplifier configured to amplify one output beam of the bifurcated beams to output a first emitted beam; and a second semiconductor optical amplifier configured to amplify another output beam of the bifurcated beams to output a second emitted beam. The control device is configured to perform wavelength switching control on wavelengths of the first emitted beam and the second emitted beam by switching an electric power input to the second semiconductor optical amplifier.

Abstract: An optical transmission apparatus (100) includes an optical transmitter (200) including an optical modulator (220) and an observation optical modulator (230) that attenuate optical power of input continuous wave light by an electro-absorption effect and output the continuous wave light. The optical modulator (220) performs pulse amplitude modulation on the continuous wave light and outputs the optical signal.

Abstract: An optical transmission apparatus includes an optical transmitter including an optical modulator and an observation optical modulator that attenuate optical power of input continuous wave light by an electro-absorption effect and output the light. The optical modulator performs pulse amplitude modulation on the continuous wave light and outputs the optical signal. The apparatus also includes: a bias voltage generation unit that generates a direct-current bias voltage and outputs the direct-current bias voltage to the optical modulator and the observation optical modulator; a modulation signal generation unit that generates an electrical signal for pulse amplitude modulation and outputs the electrical signal to the optical modulator; and a bias voltage control unit that instructs the bias voltage generation unit to adjust the direct-current bias voltage on the basis of an absorption amount of optical power in the optical modulator and an absorption amount of optical power in the observation optical modulator.

Abstract: A wavelength tunable light source includes a wavelength tunable laser device and a control device. The wavelength tunable laser device includes: M laser diodes configured to generate laser oscillation to output beams; a multiplexer/demultiplexer configured to multiplex the beams output from the M laser diodes to bifurcate the beams for output; a first semiconductor optical amplifier configured to amplify one output beam of the bifurcated beams to output a first emitted beam; and a second semiconductor optical amplifier configured to amplify another output beam of the bifurcated beams to output a second emitted beam. The control device is configured to perform wavelength switching control on wavelengths of the first emitted beam and the second emitted beam by switching an electric power input to the second semiconductor optical amplifier.

Abstract: An optical detector module includes a carrier, a photodetector secured to a top surface of the carrier and having a light detecting portion, an anode terminal, and a cathode terminal, an amplifier circuit secured to the top surface of the carrier and having a first edge, an input terminal, and a GND terminal. The input terminal and the GND terminal are located along the first edge. A first wire connects the anode terminal to the input terminal, and to a composite component secured to the top surface of the carrier and having a metal portion and a resistive portion integrated together. The metal portion is in contact with the carrier. A capacitor, having a top surface electrode and a bottom surface electrode is secured to the carrier.

Abstract: The transmittance of a filter periodically varies with respect to the incident light frequency. Provided that fk is the sum of Fk and ?k, or the difference obtained by subtracting Fk from ?k, depending on the kth light source among multiple light sources, an incidence guide causes light from the plurality of light sources to be incident on the filter such that the propagation angle of light when light from the kth light source propagates through the interior of the filter equals ?k obtained by computation using fk. The incidence guide causes light to be incident on the filter, taking fk to be the sum of ?k and Fk for at least one of the light sources, and taking fk to be the difference between ?k and Fk for at least one other of the light sources. A detector detects the intensity of transmitted light that transmits through the filter.

Abstract: An optical detector module includes a carrier, a photodetector secured to a top surface of the carrier and having a light detecting portion, an anode terminal, and a cathode terminal, an amplifier circuit secured to the top surface of the carrier and having a first edge, an input terminal, and a GND terminal. The input terminal and the GND terminal are located along the first edge. A first wire connects the anode terminal to the input terminal, and to a composite component secured to the top surface of the carrier and having a metal portion and a resistive portion integrated together. The metal portion is in contact with the carrier. A capacitor, having a top surface electrode and a bottom surface electrode is secured to the carrier.

Abstract: The transmittance of a filter periodically varies with respect to the incident light frequency. Provided that fk is the sum of Fk and vk, or the difference obtained by subtracting Fk from vk, depending on the kth light source among multiple light sources, an incidence guide causes light from the plurality of light sources to be incident on the filter such that the propagation angle of light when light from the kth light source propagates through the interior of the filter equals ?k obtained by computation using fk. The incidence guide causes light to be incident on the filter, taking fk to be the sum of vk and Fk for at least one of the light sources, and taking fk to be the difference between vk and Fk for at least one other of the light sources. A detector detects the intensity of transmitted light that transmits through the filter.

Abstract: An optical transmitter includes an equalizer which receives a data signal, an optical modulator driver which amplifies an output signal of the equalizer, and an optical modulator which converts an output signal of the optical modulator driver into an optical signal and outputs the optical signal. The equalizer has a signal line for transmitting the data signal, a coupled line electromagnetically coupled to the signal line, a resistive section connected to the coupled line, and a ground via connected to the resistive section. The equalizer reduces power of the data signal in a frequency range where the frequency response characteristic of the optical modulator driver exhibits peaking, to reduce waveform jitter in the output signal of the optical modulator driver that is input to the optical modulator.