Patent ID: 7083995
Filing Date: 2006-08-01
Classification: G02F,H01S

Abstract:
1. A process for producing an optical semiconductor device comprising a plurality of a semiconductor lasers which oscillate longitudinal single mode laser beams with different wavelengths and have been simultaneously formed on a single substrate, said process comprising the steps of: coating a resist on the substrate; exposing the surface of the resist to form a pattern of a plurality of diffraction gratings, said pattern set to a predetermined shape for setting pitches corresponding respectively to oscillation wavelengths for the plurality of semiconductor lasers and for setting each diffraction grating heights to provide a substantially similar coupling coefficient for each laser independently of the oscillation wavelength of each laser; etching the substrate in such a manner that the level of etching per unit time is identical; patterning a mask to give a predetermined shape according to the arrangement of the diffraction gratings; forming a laser active layer on each of the diffraction gratings using the mask having a predetermined shape by a selective MOVPE growth method (metal-organic vapor phase epitaxy); and forming an electrode on each of the top surface of the laser active layer and the backside of the substrate.