Abstract:
This present invention is provided with: a semiconductor laser for emitting laser light in a plurality of channels; optical waveguides optically coupled in a corresponding manner to the semiconductor lasers, the optical waveguides propagating laser light as input light for each channel; optical modulators for modulating the input light and generating an optical signal; and an optical signal output unit coupled to the optical modulators, the optical signal output unit outputting the optical signal propagated from the optical modulators to the exterior. The present invention is characterized in that the semiconductor laser is arranged on the opposite side from an optical branching unit and the optical modulators, with the optical signal output unit interposed therebetween, in the plane of an opto-electric hybrid board.
Abstract:
An optical element includes: a first delayed interferometer; and a second delayed interferometer and a third delayed interferometer cascaded to the first delayed interferometer. The first delayed interferometer includes: a first optical coupler and a second optical coupler; a first waveguide between the first optical coupler and the second optical coupler; a second waveguide between the first optical coupler and the second optical coupler, the second waveguide being longer than the first waveguide; and a ring waveguide that is coupled to the first waveguide. A difference between a length of the first waveguide and a length of the second waveguide differs from a difference in lengths corresponding to a channel spacing by a length corresponding to a phase displacement caused by loading of the ring waveguide.
Abstract:
A modulated light source includes a ring modulator, a first optical waveguide and a second optical waveguide that are optically connected to the ring modulator, and a third optical waveguide that optically connects an end of the first optical waveguide and an end of the second optical waveguide. At least part of the third optical waveguide has optical gain, and an optical waveguide loop including the ring modulator, the first optical waveguide, the second optical waveguide, and the third optical waveguide is used as a resonator to cause laser oscillation.
Abstract:
An optical circuit, wherein the effects of reflected light generated by an optical component are reduced. The optical circuit (100) is provided with an optical branching (110) for branching light, an optical coupler (114) for coupling a first portion of branched light to an optical waveguide (118) for transmission, and an optical reflecting unit (116) for reflecting a second portion of the branched light, the phase difference between the reflected light from the optical coupler (114) and the reflected light from the optical reflecting unit (116) being (2m−1)π (where m is an integer) on an input side of the optical branching (110).
Abstract:
There is provided a bidirectional optical communication module including a bidirectional optical communication chip configured to include an optical circuit board in which a light receiving element constituting a receiving section, a transmitting element constituting a transmitting section, and a wavelength-division multiplexing (WDM) filter that divides transmission signal light and reception signal light from each other are hybrid-integrated, a reflecting section configured to direct a propagation direction of the transmission signal light output from the transmitting section and the reception signal light received by the receiving section to a direction orthogonal to the optical circuit board, and an optical coupling element configured to spatially optically-couple an input-output port for the transmission signal light and the reception signal light provided at the bidirectional optical communication chip to an input-output port of an optical fiber.
Abstract:
An optical receiving circuit which suppresses a characteristic deterioration due to a wiring between a PD and a TIA and a method for manufacturing the optical receiving circuit are provided. A optical receiving circuit (300) comprises a photodiode (302), and a transimpedance amplifier (308) that supplies an electrical power source to the photodiode (302). The characteristic impedance of a wiring between the anode of the photodiode (302) and the transimpedance amplifier (308) is higher than the characteristic impedance of a wiring between the cathode of the photodiode (302) and the transimpedance amplifier (308).
Abstract:
An optical end coupling type silicon optical integrated circuit is provided using an SOI substrate. This optical integrated circuit is constituted so as to connect with an external optical circuit at an end coupling part and have signal light incident to an optical circuit that includes a curved part. In the plane of the optical integrated circuit, the position of one end coupling part selected from among any thereof and the position of any multimode optical waveguide element to which a respective optical waveguide is connected via a respective curved part satisfy a positional relationship defined on the basis of a beam divergence angle [theta] of stray light.
Abstract:
A control method of an optical element, including light sources to emit lights having different wavelengths from each other, and ring modulators connected in cascade along a light waveguide, is disclosed. Each ring modulator includes a ring resonator, and a wavelength adjustment electrode to adjust a resonance wavelength in the ring resonator, wherein the lights from the light sources are multiplexed to enter the light waveguide. The method includes having a light source emit the light; adjusting power to the wavelength adjustment electrode in each ring modulator, to obtain a value of the power causing the resonance wavelength of the ring resonator, equivalent to the wavelength of the light emitted from the light source; obtaining a relationship between the light sources and the values of the power corresponding to the ring modulators; and selecting the ring modulators corresponding to the light sources based on the relationship.
Abstract:
A wavelength demultiplexer includes a photonic circuit and a control circuit that adjusts wavelength characteristics of the photonic circuit. The photonic circuit converts two orthogonal polarized waves contained in the incident light into two same polarized waves, which are supplied to a first optical demultiplexing circuit and a second optical demultiplexing circuit provided in the photonic circuit and having the same configuration. The photonic circuit supplies a total output power of monitor lights extracted from the same positions in the first optical demultiplexing circuit and the second optical demultiplexing circuit to the control circuit. The control circuit controls a first wavelength characteristic of the first optical demultiplexing circuit and a second wavelength characteristic of the second optical demultiplexing circuit based on the total output power of the monitor lights.