Patent ID: 6567444
Filing Date: 2003-05-20
Classification: H01S

Abstract:
A semiconductor laser device comprising:a substrate; an active region formed above said substrate; and a non-absorbing layer formed over said active region, and made of a semiconductor material having a bandgap greater than photon energy of laser light which oscillates in said semiconductor laser device; said active region includes, a first lower optical waveguide layer formed above said substrate, an etching stop layer formed on said first lower optical waveguide layer except for near-edge areas of said first lower optical waveguide layer which are adjacent to opposite end facets of said semiconductor laser device, where said opposite end facets are perpendicular to a direction of said laser light, a second lower optical waveguide layer formed on said etching stop layer, a quantum well active layer formed on said second lower optical waveguide layer, a first upper optical waveguide layer formed on said quantum well active layer, an electron barrier layer formed on said first upper optical waveguide layer and made of a semiconductor material having a bandgap greater than a bandgap of said first upper optical waveguide layer, and a second upper optical waveguide layer formed on said electron barrier layer; said etching stop layer has such a chemical property that said etching stop layer can be maintained when said second lower optical waveguide layer, said quantum well active layer, said first upper optical waveguide layer, and said electron barrier layer are etched, and said first lower optical waveguide layer can be maintained when the etching stop layer is etched.