Abstract:
In an optical transmitter comprising a directly modulated laser and a wavelength filter provided on a post-stage of the directly modulated laser, the wavelength filter has a modulated light input port for inputting modulated light output from the directly modulated laser, a filter transmitted light output port for outputting light having a wavelength included in a filter transmission band among the modulated light as filter transmitted light, and a filter cutoff light output port provided separately from the modulated light input port and the filter transmitted light output port and outputting light having a wavelength included in a filter cutoff band among the modulated light as filter cutoff light, and the peak of the filter transmission band is set on a shorter-wave side from the peak of the spectrum of modulated light output from the directly modulated laser.
Abstract:
An optical interference unit branching inputted input light into two optical waveguides, combining the respective branched lights propagating through the respective optical waveguides and outputting modulated light is included, and bias voltage supplied to at least one optical waveguide out of the two optical waveguides is controlled in accordance with wavelength of the input light. Further, a phase of the modulated light is controlled by phase adjusting voltage in accordance with the wavelength of the input light.
Abstract:
In an optical transmitter comprising a directly modulated laser and a wavelength filter provided on a post-stage of the directly modulated laser, the wavelength filter has a modulated light input port for inputting modulated light output from the directly modulated laser, a filter transmitted light output port for outputting light having a wavelength included in a filter transmission band among the modulated light as filter transmitted light, and a filter cutoff light output port provided separately from the modulated light input port and the filter transmitted light output port and outputting light having a wavelength included in a filter cutoff band among the modulated light as filter cutoff light, and the peak of the filter transmission band is set on a shorter-wave side from the peak of the spectrum of modulated light output from the directly modulated laser.
Abstract:
In an optical transmitter comprising a directly modulated laser and a wavelength filter provided on a post-stage of the directly modulated laser, the wavelength filter has a modulated light input port for inputting modulated light output from the directly modulated laser, a filter transmitted light output port for outputting light having a wavelength included in a filter transmission band among the modulated light as filter transmitted light, and a filter cutoff light output port provided separately from the modulated light input port and the filter transmitted light output port and outputting light having a wavelength included in a filter cutoff band among the modulated light as filter cutoff light, and the peak of the filter transmission band is set on a shorter-wave side from the peak of the spectrum of modulated light output from the directly modulated laser.
Abstract:
An optical interference unit branching inputted input light into two optical waveguides, combining the respective branched lights propagating through the respective optical waveguides and outputting modulated light is included, and bias voltage supplied to at least one optical waveguide out of the two optical waveguides is controlled in accordance with wavelength of the input light. Further, a phase of the modulated light is controlled by phase adjusting voltage in accordance with the wavelength of the input light.
Abstract:
In an optical transmitter comprising a directly modulated laser and a wavelength filter provided on a post-stage of the directly modulated laser, the wavelength filter has a modulated light input port for inputting modulated light output from the directly modulated laser, a filter transmitted light output port for outputting light having a wavelength included in a filter transmission band among the modulated light as filter transmitted light, and a filter cutoff light output port provided separately from the modulated light input port and the filter transmitted light output port and outputting light having a wavelength included in a filter cutoff band among the modulated light as filter cutoff light, and the peak of the filter transmission band is set on a shorter-wave side from the peak of the spectrum of modulated light output from the directly modulated laser.
Abstract:
A semiconductor laser includes: a first portion, made from a silicon-containing material, including an optical waveguide, a first diffraction grating including a phase shift, and a second diffraction grating; a second portion including a light-emitting layer made from a material different from that of the first portion; a laser region including the first diffraction grating, and the optical waveguide and the light-emitting layer provided in a position corresponding to the first diffraction grating; and a mirror region including the second diffraction grating, and the optical waveguide and the light-emitting layer provided in a position corresponding to the second diffraction grating.
Abstract:
There are provided first and second optical waveguides formed on a semiconductor substrate and having upper clad layers and core layers that are separated mutually respectively, first and second phase modulation electrodes formed on the first and second optical waveguides respectively, and first and second slot-line electrodes formed on the semiconductor substrate on both sides of the first and second optical waveguides and connected to the first and second phase modulation electrodes via air-bridge wirings separately respectively.
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 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.