An optoelectronic device. The optoelectronic device comprising: a rib waveguide provided on a substrate of the device, the rib waveguide comprising a ridge portion and a slab portion; a heater, disposed within the slab portion; a thermally isolating trench, adjacent to the rib waveguide, and extending into the substrate of the device; and a thermally isolating cavity within the substrate, which is directly connected to the thermally isolating trench, and which extends across at least a part of a width of the rib waveguide between the rib waveguide and the substrate.

A light reception device of the present invention includes a first i-type cladding region, an n-type waveguide core having a predetermined width, and a second i-type cladding region in contact with a side surface of the n-type waveguide core on a substrate, includes a p-type absorption layer, a p-type diffusion barrier layer, a p-type contact layer, and a p-type electrode formed in an upper part above a region including a part of the n-type waveguide core, with an i-type insertion layer interposed between the upper part and the region, and includes an n-type electrode on an upper surface of another part of the n-type waveguide core.

A phase shifter includes functional actively controlled phase-shift elements formed with TSVs. The phase shifter may include plural phase shifter elements each including: a signal line including a signal line through-substrate-via (TSV) in a substrate; a ground return line including a ground return line TSV in the substrate; a capacitance control line including a capacitance control line TSV in the substrate; and an inductance control line including an inductance control line TSV in the substrate, wherein the phase shifter element has one of a first phase shift and a second phase shift, different from the first phase shift, based on a capacitance and an inductance of the signal line TSV.

A phase shifter includes functional actively controlled phase-shift elements formed with TSVs. The phase shifter may include plural phase shifter elements each including: a signal line including a signal line through-substrate-via (TSV) in a substrate; a ground return line including a ground return line TSV in the substrate; a capacitance control line including a capacitance control line TSV in the substrate; and an inductance control line including an inductance control line TSV in the substrate, wherein the phase shifter element has one of a first phase shift and a second phase shift, different from the first phase shift, based on a capacitance and an inductance of the signal line TSV.

An optical modulator. The optical modulator comprising: a micro-ring resonator; and a bus waveguide, including an input waveguide region, an output waveguide region, and a coupling waveguide region optically coupled to the micro-ring resonator and located between the input waveguide region and the output waveguide region. The micro-ring resonator includes a modulation region, the modulation region being formed of a silicon portion and a III-V semiconductor portion separated by a crystalline rare earth oxide dielectric layer.

An optical modulator. The optical modulator comprising: a micro-ring resonator; and a bus waveguide, including an input waveguide region, an output waveguide region, and a coupling waveguide region optically coupled to the micro-ring resonator and located between the input waveguide region and the output waveguide region. The micro-ring resonator includes a modulation region, the modulation region being formed of a silicon portion and a III-V semiconductor portion separated by a crystalline rare earth oxide dielectric layer.

In an optical transmitter having an electro-optic modulator with first child MZI and a second child MZI nested to form a parent MZI, and a processor that controls the bias voltages of electro-optic modulator. In the first section of a control loop, the processor simultaneously superimposes different dither signals onto the first bias voltage of the first child MZI and 1.0 the second bias voltage of the second child MZI, and extracts the first phase error information for the first child MZI and the first-round third phase error for the parent MZI from a first monitoring result. In the second section of the control loop, the processor simultaneously superimposes different dither signals onto the first and second bias voltages, and extracts the second phase error information for the second child MZI and the second-round third phase error for the parent MZI from a second monitoring result.

In an optical transmitter having an electro-optic modulator with first child MZI and a second child MZI nested to form a parent MZI, and a processor that controls the bias voltages of electro-optic modulator. In the first section of a control loop, the processor simultaneously superimposes different dither signals onto the first bias voltage of the first child MZI and 1.0 the second bias voltage of the second child MZI, and extracts the first phase error information for the first child MZI and the first-round third phase error for the parent MZI from a first monitoring result. In the second section of the control loop, the processor simultaneously superimposes different dither signals onto the first and second bias voltages, and extracts the second phase error information for the second child MZI and the second-round third phase error for the parent MZI from a second monitoring result.

A phase shifter includes a substrate, waveguides and a wiring portion. The substrate includes optical waveguide regions and contact regions. Each contact region has contact portions. The waveguides are disposed at the substrate, and each of the waveguides accumulates carriers to modulate a phase of light for guiding propagation of the light. The wiring portion electrically connects each of the waveguides and each of the contact portions. Each of the contact portions connecting each of the waveguides to a corresponding one of electrodes to inject the carriers into each of the waveguides. Each of the waveguides has a lengthwise direction defined as a first direction, and a direction that is perpendicular to the first direction and is parallel to a surface of the substrate is defined as a second direction. The optical waveguide regions and the contact regions are disposed to be alternately aligned along the second direction.

A phase shifter includes a substrate, waveguides and a wiring portion. The substrate includes optical waveguide regions and contact regions. Each contact region has contact portions. The waveguides are disposed at the substrate, and each of the waveguides accumulates carriers to modulate a phase of light for guiding propagation of the light. The wiring portion electrically connects each of the waveguides and each of the contact portions. Each of the contact portions connecting each of the waveguides to a corresponding one of electrodes to inject the carriers into each of the waveguides. Each of the waveguides has a lengthwise direction defined as a first direction, and a direction that is perpendicular to the first direction and is parallel to a surface of the substrate is defined as a second direction. The optical waveguide regions and the contact regions are disposed to be alternately aligned along the second direction.