An electrically-operated semiconductor laser device and method for forming the laser device are provided. The laser device includes a fin structure to which a waveguide is optically coupled. The waveguide is optically coupled to passive waveguides at either end thereof. The fin structure includes an array of fin elements, each fin element comprising Group III-V materials.

III-V lasers integrated with silicon photonic circuits and methods for making the same include a three-layer semiconductor stack formed from III-V semiconductors on a substrate, where a middle layer has a lower bandgap than a top layer and a bottom layer; a mirror region monolithically formed at a first end of the stack, configured to reflect emitted light in the direction of the stack; and a waveguide region monolithically formed at a second end of the stack, configured to transmit emitted light.

A semiconductor optical amplifier array device includes: a substrate; and a plurality of semiconductor optical amplifiers formed on the substrate, each of the semiconductor optical amplifiers including an active region, and two input-output ports optically connected to the active region and disposed on same facet of the semiconductor optical amplifier array device. The plurality of semiconductor optical amplifiers include a first semiconductor optical amplifier in which length of the active region is equal to a first length, and a second semiconductor optical amplifier in which length of the active region is equal to a second length that is different from the first length.