Patent ID: 8705583
Filing Date: 2014-04-22
Classification: B82Y,H01S

Abstract:
1. A semiconductor laser, comprising: a distributed feedback laser region including an active layer, and a diffraction grating and a phase shift which determine a single oscillation wavelength and provided over or under the active layer, the distributed feedback laser region being a current injection region; and a distributed reflector region including a passive waveguide core layer jointed to an end face of the active layer and a reflection diffraction grating provided over or under the passive waveguide core layer and continuing to the diffraction grating, the distributed reflector region being a no-current injection region; and wherein the diffraction grating in the distributed feedback laser region has a fixed period; the distributed reflector region has an effective diffraction grating period which varies along a direction of a cavity; and the effective diffraction grating period of the distributed reflector region becomes longer as a distance from the distributed feedback laser region increases over the entire region.