Patent ID: 7564884

Claim:
A semiconductor laser having a resonator formed on a semiconductor substrate, the resonator including: a 1 st cladding layer; an active layer disposed on the 1 st cladding layer; a 2 nd cladding layer disposed on the active layer and having a stripe ridge portion; an insulating layer disposed on the 2 nd cladding layer so as not to cover an upper surface of the ridge portion; and a front film and a rear film disposed on each end face of the resonator, wherein the front film has a smaller reflectance than the rear film, and the insulating layer includes, on a side close to the front film, a 1 st insulating film having a 1 st refractive index and, on a side close to the rear film, a 2 nd insulating film having a 2 nd refractive index, the 1 st refractive index being larger than the 2 nd refractive index.