Patent ID: 9564737
Date: 2017-02-07
CPC Classifications: H01S

Claim:
1. An optical semiconductor device comprising: an n-type semiconductor substrate; a semiconductor laser section formed on the n-type semiconductor substrate and including an active layer worked into a mesa stripe shape and a p-type cladding layer formed on the active layer; an optical waveguide section formed on an optical output side of the active layer on the n-type semiconductor substrate and including an optical waveguide layer worked into a mesa stripe shape and an upper cladding layer formed on the optical waveguide layer; a semiconductor current constriction layer embedding both sides of the active layer and the optical waveguide layer; a p-type semiconductor layer formed on the semiconductor laser section; and a leakage current suppression layer formed on the optical waveguide section, wherein the upper cladding layer includes a first low carrier concentration layer having a lower carrier concentration than the p-type cladding layer and a first Fe-doped semiconductor layer formed on the first low carrier concentration layer, the leakage current suppression layer includes a second Fe-doped semiconductor layer disposed on a side of the p-type semiconductor layer, the first low carrier concentration layer has a side wall part that is in contact with a side face of the p-type cladding layer, and the first Fe-doped semiconductor layer is disposed on a side of the p-type cladding layer via the side wall part of the first low carrier concentration layer and is not in contact with the p-type cladding layer.