Patent ID: 8913897

Claim:
A laser diode, comprising: a semiconductor substrate; a waveguide layer disposed on the semiconductor substrate, the waveguide layer comprising a quantum well layer; a light wave limiting layer disposed on a surface of the waveguide layer, the light wave limiting layer being configured to limit a light wave to be transmitted within the waveguide layer; wherein the quantum well layer comprises a plurality of quantum well regions disposed along a transmission direction of the light wave and the quantum well regions respectively have gain peaks of different wavelengths; wherein the quantum well layer has a stepped structure, and the quantum well regions have thickness different from one another; wherein the quantum well regions comprise: a first quantum well region, a second quantum well region and a third quantum well region; a wavelength of a gain peak of the second quantum well region is greater than a wavelength of a gain peak of the first quantum well region but is less than a wavelength of a gain peak of the third quantum well region; wherein when the temperature rises, the injection current of the first quantum well region is increased to compensate gain spectrum drift resulted from rise of the temperature; and when the temperature drops, the injection current of the third quantum well region is increased to compensate gain spectrum drift resulted from drop of the temperature.