Patent ID: 7983318
Filing Date: 2011-07-19
Classification: B82Y,G02B,H01S

Abstract:
1. An optical semiconductor device, comprising: a semiconductor laser; a first optical waveguide connected to the semiconductor laser; an optical coupler adapted to branch light guided from the semiconductor laser through the first optical waveguide into two lights; two second optical waveguides connected to the optical coupler; a diffraction grating provided in each of the two second optical waveguides; and an optical detector adapted to detect light guided through one of the two diffraction gratings; and wherein the semiconductor laser, the first optical waveguide, the optical coupler, the second optical waveguides, the diffraction gratings and the optical detector are integrated on the same substrate; and the optical semiconductor device is adapted such that phases of reflection returning light from the diffraction gratings side are displaced by .pi. from each other at a location of the optical coupler so that the reflection returning lights from the diffraction gratings side to the semiconductor laser side interfere with each other and thereby extinguish each other at the optical coupler.