A method for fabricating a buried heterostructure semiconductor optical amplifier is provided. The method includes a step providing a patterned dielectric layer on a substrate, the patterned dielectric layer having openings to expose uncovered regions of the substrate. The method also includes, in a single metal organic chemical vapour deposition (MOCVD) run: etching the uncovered regions of the substrate to form angles at corresponding edges thereof and diffusing a p-dopant in the substrate to obtain a p-dopant distribution in a portion of the substrate; etching a portion of the p-dopant thereby defining a recess in the substrate and growing a n-blocking layer in the recess; sequentially growing, over a portion of the n-blocking layer, an active region, a p-overclad, a p-contact, and a p-metal contact; and growing a n-metal contact on a backside of the substrate. The single MOCVD run combines selective area growth, p-dopant diffusion and etching techniques.

A tunable laser that is characterized by including a gain waveguide ACT made of an optically active semiconductor material, and a tunable wavelength filter TWF that selects light of a specific wavelength using current injection, which are integrated on a compound semiconductor substrate S, in which at least one or more of the tunable wavelength filters TWF are formed to select a specific wavelength of light from the light from the waveguide ACT and return the selected specific wavelength of light back to the waveguide ACT, and a semiconductor mixed crystal material constituting the tunable wavelength filter TWF has a strained multiple quantum well structure MQW in which a mixed crystal material ratio changes periodically.

A LiDAR system including a laser amplification system is disclosed. The laser amplification system includes a laser source and an optical amplifier. The laser source has a laser cavity and is configured to output electromagnetic radiation. The optical amplifier includes quantum dots and is positioned outside the laser cavity to receive the electromagnetic radiation output from the laser source. The optical amplifier amplifies the received electromagnetic radiation using the quantum dots and outputs the amplified electromagnetic radiation.

A LiDAR system including a laser amplification system is disclosed. The laser amplification system includes a laser source and an optical amplifier. The laser source has a laser cavity and is configured to output electromagnetic radiation. The optical amplifier includes quantum dots and is positioned outside the laser cavity to receive the electromagnetic radiation output from the laser source. The optical amplifier amplifies the received electromagnetic radiation using the quantum dots and outputs the amplified electromagnetic radiation.

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.

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.

An optical device is provided that includes an active waveguide having a top electrode and a plurality of layers including a gain layer. Configurations are disclosed for the active waveguide to enable amplification of a guided optical wave profile while preserving a shape of a lateral optical intensity profile of the guided optical wave as the guided optical wave is amplified along the waveguide. The top electrode and/or one or more layers of the active optical waveguide may be tailored to provide a tailored optical gain.

An optical device is provided that includes an active waveguide having a top electrode and a plurality of layers including a gain layer. Configurations are disclosed for the active waveguide to enable amplification of a guided optical wave profile while preserving a shape of a lateral optical intensity profile of the guided optical wave as the guided optical wave is amplified along the waveguide. The top electrode and/or one or more layers of the active optical waveguide may be tailored to provide a tailored optical gain.

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 semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers include: a first quantum dot layer doped with a p-type impurity; and a second quantum dot layer doped with an n-type impurity and having an emission wavelength different from that of the first quantum dot layer.