Abstract: A wavelength tunable laser device includes: a first mirror; a second mirror; an optical amplifier provided between the first mirror and the second mirror; a wavelength tunable filter provided between the first mirror and the second mirror; and an optical waveguide coupling the optical amplifier and the wavelength tunable filter. The optical waveguide includes a first waveguide formed with a first width and a second waveguide formed with a second width wider than the first width.

Abstract: A wavelength filter includes a first filter circuit and a second filter circuit. The first filter circuit that has a passband that is obtained from a vernier effect by connecting, in series, a plurality of ring resonators each having a different transmission wavelength interval and that is within a gain band of an optical amplifier, and that passes, from the gain band, light at a selected wavelength and light that has a wavelength in a recursive mode and that is produced on a short wavelength side or a long wavelength side of the selected wavelength. The second filter circuit is connected to the first filter circuit in series and suppresses the light at the wavelength in the recursive mode from the light passing through the first filter circuit.

Abstract: An optical amplifier includes a polarization splitter, a polarization rotator, first and second optical couplers, and first and second semiconductor optical amplifying devices. The TE polarized wave of light split by the polarization splitter is input to a first input port of the first optical coupler. The TM polarized wave of the split light is converted into a TE polarized wave by the polarization rotator to be input to a second input port of the first optical coupler. First light and second light output from a first output port and a second output port of the first optical coupler are amplified by the first semiconductor optical amplifying device and the second semiconductor optical amplifying device to be input to a first input port and a second input port of the second optical coupler, respectively. Third light is output from an output port of the second optical coupler.

Abstract: An optical amplifier includes an optical amplifier chip that includes a pair of semiconductor optical amplifiers (SOAs), a U-shaped waveguide connecting the pair of SOAS, and two electrodes that respectively correspond to the pair of SOAS and are separated from each other, and a base substrate that includes a common metal wiring connecting the two electrodes, and on which the optical amplifier chip is mounted.

Abstract: An optical transceiver device includes: an optical circuit that includes an optical modulator to generate a modulated optical signal and an optical reception circuit to convert a received optical signal into an electric signal and implemented in a rectangular optical circuit area; a driver circuit that drives the optical modulator and arranged along a first side of the optical circuit area; an amplifier circuit that converts an output signal of the optical reception circuit into a voltage signal and arranged along a second side of the optical circuit area, the second side being orthogonal to the first side; a first electrical component that is electrically coupled to the driver circuit and arranged in an area adjacent to the driver circuit; and a second electrical component that is electrically coupled to the amplifier circuit and arranged in an area adjacent to the amplifier circuit.

Abstract: A wavelength locker includes a splitter configured to split a portion of light that is output from a light source into a first monitoring light and a second monitoring light; a first periodic filter configured to receive the first monitoring light; a second periodic filter configured to receive the second monitoring light; a first optical receiver configured to monitor an intensity of light that has passed through the first periodic filter; and a second optical receiver configured to monitor an intensity of light that has passed through the second periodic filter, wherein the first periodic filter and the second periodic filter each has a wavelength characteristic in which an intensity of transmitted light changes periodically with respect to a wavelength, and the wavelength characteristic of the first periodic filter and the wavelength characteristic of the second periodic filter shift in opposite wavelength directions when temperature changes.

Abstract: An optical transceiver device includes: an optical circuit that includes an optical modulator to generate a modulated optical signal and an optical reception circuit to convert a received optical signal into an electric signal and implemented in a rectangular optical circuit area; a driver circuit that drives the optical modulator and arranged along a first side of the optical circuit area; an amplifier circuit that converts an output signal of the optical reception circuit into a voltage signal and arranged along a second side of the optical circuit area, the second side being orthogonal to the first side; a first electrical component that is electrically coupled to the driver circuit and arranged in an area adjacent to the driver circuit; and a second electrical component that is electrically coupled to the amplifier circuit and arranged in an area adjacent to the amplifier circuit.

Abstract: A apparatus includes a tunable laser configured to include a tunable filter and a mirror; a first optical splitter provided between the tunable filter and the mirror, the first optical splitter including a first port and a second port on a tunable filter side and a third port and a fourth port on a mirror side, in which the tunable filter is coupled to the first port and the mirror is coupled to the third port, respectively; a first optical waveguide coupled to the second port; a second optical waveguide coupled to the fourth port; and an optical coupler with which the first optical waveguide and the second optical waveguide are combined.

Abstract: An optical amplifier includes a polarization splitter, a polarization rotator, first and second optical couplers, and first and second semiconductor optical amplifying devices. The TE polarized wave of light split by the polarization splitter is input to a first input port of the first optical coupler. The TM polarized wave of the split light is converted into a TE polarized wave by the polarization rotator to be input to a second input port of the first optical coupler. First light and second light output from a first output port and a second output port of the first optical coupler are amplified by the first semiconductor optical amplifying device and the second semiconductor optical amplifying device to be input to a first input port and a second input port of the second optical coupler, respectively. Third light is output from an output port of the second optical coupler.

Abstract: A wavelength locker includes a splitter configured to split a portion of light that is output from a light source into a first monitoring light and a second monitoring light; a first periodic filter configured to receive the first monitoring light; a second periodic filter configured to receive the second monitoring light; a first optical receiver configured to monitor an intensity of light that has passed through the first periodic filter; and a second optical receiver configured to monitor an intensity of light that has passed through the second periodic filter, wherein the first periodic filter and the second periodic filter each has a wavelength characteristic in which an intensity of transmitted light changes periodically with respect to a wavelength, and the wavelength characteristic of the first periodic filter and the wavelength characteristic of the second periodic filter shift in opposite wavelength directions when temperature changes.

Abstract: A apparatus includes a tunable laser configured to include a tunable filter and a mirror; a first optical splitter provided between the tunable filter and the mirror, the first optical splitter including a first port and a second port on a tunable filter side and a third port and a fourth port on a mirror side, in which the tunable filter is coupled to the first port and the mirror is coupled to the third port, respectively; a first optical waveguide coupled to the second port; a second optical waveguide coupled to the fourth port; and an optical coupler with which the first optical waveguide and the second optical waveguide are combined.

Abstract: An optical modulation device includes: an optical waveguide formed above a substrate; a phase modulator disposed on part of the optical waveguide; a capacitor connected to the phase modulator and including a lower electrode and an upper electrode; a resistor connected in parallel to the capacitor; and an appended part integrated with the upper electrode and electrically connected to the resistor, wherein the appended part is smaller in area than the capacitor (upper electrode).

Abstract: An optical element includes a first optical waveguide that extends from a first end portion toward a second end portion, and has a first active layer, a second optical waveguide that has a second active layer, and is disposed side by side with the first optical waveguide and extends from the first end portion toward the second end portion, a reflective film disposed on an end face of the first optical waveguide at a side of the first end portion, and an anti-reflection film disposed on an end face of the second optical waveguide at the side of the first end portion, wherein the anti-reflection film extends from a side of the second optical waveguide to the first optical waveguide at the first end portion, and the reflective film includes the anti-reflection film as one of constituent elements.

Abstract: An optical modulation device includes: an optical waveguide formed above a substrate; a phase modulator disposed on part of the optical waveguide; a capacitor connected to the phase modulator and including a lower electrode and an upper electrode; a resistor connected in parallel to the capacitor; and an appended part integrated with the upper electrode and electrically connected to the resistor, wherein the appended part is smaller in area than the capacitor (upper electrode).

Abstract: An optical distance measuring system includes a multi-wavelength pulse light source configured to generate a plurality of light pulses of different wavelengths and repeat a cycle in which the light pulse is generated while sequentially changing the wavelength thereof; a scan device configured to scan the light pulses; a wavelength-selectable light receiver configured to receive reflection light of the plurality of light pulses of difference wavelengths from a target and generate a light receiving signal that corresponds to each of the plurality of different wavelengths; and a processor configured to detect time from the generation of each of the plurality of light pulses of different wavelengths in the multi-wavelength pulse light source to the generation of the light receiving signal of a corresponding wavelength which is generated in predetermined time and calculate a distance to the target in a scanning direction from the detected time.

Abstract: A phase modulation device including a diode-type phase modulator having a pair of side terminals connected to two sides of an optical waveguide core along an optical axis of the optical waveguide core, and a control unit that controls electrical signals to be input to the phase modulator, the side terminal of the phase modulator being divided into a plurality of portions along the optical axis of the optical waveguide core, the phase modulator having electrodes 15 respectively provided on the divided side terminals and electrically separated from each other, the control unit having switches and constant-current sources connected to the electrodes of the side terminals and controls stepwise the amount of change in phase of propagating light in the optical waveguide core according to the number of the switches turned on.

Abstract: A sealing device is provided which is capable of a two-step holding operation with the use of a linear solenoid. The sealing device includes a stopping mechanism for stopping a movement of a movable part that forms the linear solenoid when the linear solenoid is driven at a predetermined midway point between a start point and an end point after the nozzle part has been moved from the waiting position to the stop position, and for releasing the movable part from a stop to allow the movable part to move again and reach the end point after the nozzle part has been returned from the stop position to the waiting position.

Abstract: The present optical modulator includes an optical waveguide core made of a semiconductor material, an electrode, and a plurality of channels made of a semiconductor material doped in an n type or a p type and electrically connecting the optical waveguide core and the electrode to each other. The plurality of channels are provided in a spaced relationship from each other along a propagation direction of light; the optical waveguide core includes a doped region doped in the n type or the p type and a non-doped region. The doped region and the non-doped region are disposed alternately along the propagation direction of light. Each of the plurality of channels is connected to the doped region.

Abstract: A phase modulation device including a diode-type phase modulator having a pair of side terminals connected to two sides of an optical waveguide core along an optical axis of the optical waveguide core, and a control unit that controls electrical signals to be input to the phase modulator, the side terminal of the phase modulator being divided into a plurality of portions along the optical axis of the optical waveguide core, the phase modulator having electrodes 15 respectively provided on the divided side terminals and electrically separated from each other, the control unit having switches and constant-current sources connected to the electrodes of the side terminals and controls stepwise the amount of change in phase of propagating light in the optical waveguide core according to the number of the switches turned on.

Abstract: The present invention provides sealing device which is capable of a two-step holding operation with the use of a linear solenoid. The sealing device includes a stopping mechanism for stopping a movement of a movable part that forms the linear solenoid when the linear solenoid is driven at a predetermined midway point between a start point and an end point after the nozzle part has been moved from the waiting position to the stop position, and for releasing the movable part from a stop to allow the movable part to move again and reach the end point after the nozzle part has been returned from the stop position to the waiting position.