An optical apparatus comprising at least two optoelectronic devices fabricated on the same substrate and in thermal communication with each other. A first optoelectronic device is configured to generate optical signals and provide them to an optical system via an optical output port. A second optoelectronic device is configured to provide heat compensation for the first optoelectronic device. An electrical circuitry provides first electrical signals to the first optoelectronic device and second electrical signals to the second optoelectronic device. The electrical circuitry is configured to adjust at least the second electrical signals to controllably adjust a temperature of the first optoelectronic device.

An optical apparatus comprising at least two optoelectronic devices fabricated on the same substrate and in thermal communication with each other. A first optoelectronic device is configured to generate optical signals and provide them to an optical system via an optical output port. A second optoelectronic device is configured to provide heat compensation for the first optoelectronic device. An electrical circuitry provides first electrical signals to the first optoelectronic device and second electrical signals to the second optoelectronic device. The electrical circuitry is configured to adjust at least the second electrical signals to controllably adjust a temperature of the first optoelectronic device.

A thermally tunable laser includes: a substrate; a laser resonator, wherein the laser resonator includes a gain section, and wherein the laser resonator includes a tuning section; a heating arrangement; a heat sink arrangement for dissipating a heat flow from the laser resonator to the heat sink arrangement; and a hole arrangement for influencing the heat flow from the laser resonator to the heat sink arrangement, wherein the hole arrangement is arranged between the substrate and the heat sink arrangement, wherein one or more holes of the hole arrangement include at least one hole being arranged within a horizontal range of the tuning section, so that a thermal resistance between the tuning section and the heat sink arrangement is increased.

A direct modulation laser includes a distributed feedback type laser active region and an optical feedback region optically connected to one end of the laser active region in a waveguide direction. The direct modulation laser performs laser oscillation by using photon-photon resonance (PPR) that occurs depending on a frequency difference between a frequency of light generated (oscillated) in the laser active region and a frequency of an FP mode in the optical feedback region.

A laser device includes a laser and a controller. The laser has an optical cavity that includes an active gain section and a phase shifter. The controller is configured to excite the active gain section to lase light out of the optical cavity. The controller is further configured to, while the light is being lased out of the optical cavity, modulate a refractive index of the phase shifter to shift an optical phase of lasing modes of the lased light to thereby reduce coherence of the lased light.

A synthesizer including a controller configured to receive a first signal. A digital-to-analog converter (DAC) is coupled to the controller and is configured to generate a voltage bias based on the first signal. The voltage bias corresponds to a target resonant frequency. A semiconductor laser is coupled to the DAC and is configured to receive a second signal tone. The semiconductor laser generates a plurality of tone signals having octave multiples of a base sub-harmonic tone of the second signal tone.

An optical waveguide structure includes a lower cladding layer positioned on a substrate; an optical guide layer positioned on the lower cladding layer; an upper cladding layer positioned on the optical guide layer; and a heater positioned on the upper cladding layer. The lower cladding layer, the optical guide layer, and the upper cladding layer constitute a mesa structure. The optical guide layer has a lower thermal conductivity than the upper cladding layer. An equation “W.sub.wg≤W.sub.mesa≤3×W.sub.wg” is satisfied, wherein W.sub.mesa represents a mesa width of the mesa structure, and W.sub.wg represents a width of the optical guide layer. The optical guide layer occupies one-third or more of the mesa width in a width direction of the mesa structure.

A light source for a frequency-modulated continuous-wave (FMCW) LiDAR device is formed by a photonic integrated circuit and comprises a substrate and a multilayer structure. Formed in the multilayer structure is a semiconductor laser that is received in a recess etched into the multilayer structure. An optical path between the semiconductor laser and a reflector forms an external cavity for the semiconductor laser. The external cavity includes a variable attenuator causing an attenuation of light guided in the cavity optical waveguide. The external cavity may also or alternatively include an optical phase modulator.

A tunable laser includes a semiconductor optical amplifier, a waveguide wavelength-tunable filter that forms the tunable laser with the semiconductor optical amplifier, an optical splitting mechanism set on a coupling optical waveguide that couples the wavelength-tunable filter and the semiconductor optical amplifier, a first optical splitter of a waveguide type that splits at least part of a light beam split by the optical splitting mechanism into two light beams, a first optical waveguide coupled to one output end of the first optical splitter, a second optical waveguide that is coupled to another output end of the first optical splitter and includes a delay waveguide, a 90° hybrid waveguide that includes two input ports to which an output light beam from the first optical waveguide and an output light beam from the second optical waveguide are input and four output ports that output four output light beams.

According to an aspect, an optical system includes a laser diode configured to emit optical signals and at least two size-switchable broken racetrack ring resonators optically coupled to an optical waveguide, where each broken racetrack ring resonator is configured to exhibit a resonant wavelength. The optical system also includes a tuning arrangement associated with the broken racetrack ring resonators, where the tuning arrangement includes a micro electro-mechanical system (MEMS) or nano electro-mechanical system (NEMS) actuator mechanically coupled to a first portion of a first one of the broken racetrack ring resonators and configured to mechanically move the first portion so as to change the resonant wavelength of the first one of the broken racetrack ring resonators.