Patent ID: 7636378

Claim:
A semiconductor laser device, comprising: a first region and a second region, wherein the first region includes an active layer provided on a semiconductor substrate, said active layer being configured for generating a laser beam; an upper cladding layer provided above the active layer; and a mesa structure, comprised of a semiconductor material provided above the active layer, wherein the second region comprises a window region at an edge of the semiconductor laser device from which the laser beam is emitted; wherein a semiconductor layer of the window region has a band gap larger than that of the energy of the laser beam; wherein the semiconductor layer of the window region comprises a stacked structure of an n-type semiconductor layer, a first semi-insulating semiconductor layer, and a p-type semiconductor layer; and wherein a first semi-insulating semiconductor into which a material selected from the group of Ru, Os, Rh, and Ti is doped is used for part of or whole of the semi-insulating semiconductor layer.