Patent ID: 8731018

Claim:
A semiconductor laser comprising: an active layer; cladding layers sandwiching the active layer; a Distributed Bragg Reflector (DBR) region including part of the active layer and parts of the cladding layers and having a diffraction grating, wherein the diffraction grating includes a diffraction grating layer, and a burying layer on and burying the diffraction grating layer and in contact with one of the cladding layers, and the diffraction grating layer has a periodic thickness; a Fabry-Perot (FP) region having no diffraction grating and including parts of the active layer, the burying layer, the diffraction grating layer, and the cladding layers; and an optical waveguide region, including parts of the active layer, the diffraction grating layer, the burying layer, and the cladding layers, located between the DBR region and a light output end surface of the semiconductor laser, wherein the optical waveguide region is longer than the DBR region in a resonator length direction of the semiconductor laser, and the parts of the active layer, the diffraction grating layer, the burying layer, and the cladding layers in the optical waveguide region have uniform thicknesses in the optical waveguide region.