Patent ID: 7835413

Claim:
A semiconductor laser comprising: a semiconductor substrate of a first conductivity type; a ridge structure supported by the semiconductor substrate, having opposed side surfaces, and including, in a stack, a first cladding layer of the first conductivity type, an active layer, and a second cladding layer of a second conductivity type, opposite the first conductivity type; and a burying layer structure in contact with the side surfaces of the ridge structure and including, in a stack, a p-type InP layer in contact with the semiconductor substrate and the side surfaces of the ridge structure, an n-type InP layer contacting the p-type InP layer, an Fe-doped semi-insulating Al(Ga)InAs layer in contact with n-type InP layer, and an Fe-doped semi-insulating InP layer in contact with and completely covering the Fe-doped semi-insulating Al(Ga)InAs layer and in contact with the p-type InP layer.