Patent ID: 7852893

Claim:
A semiconductor laser device comprising: a substrate of a first conductivity type; a laminated body of a nitride semiconductor provided on the substrate and including at least an active layer, a cladding layer of a second conductivity type having a ridge-shaped waveguide, a cladding layer of the first conductivity type provided between the substrate and the active layer; a first film provided on one end surface of an optical resonator composed of the laminated body, the first film having a reflectance of 40% or more and 60% or less; and a second film provided on the other end surface of the optical resonator and having a higher reflectance than the first film, the optical resonator having a length of 400 μm or less, the one end surface serving as a light emitting surface, the cladding layer of the first conductivity type is made of Al x Ga 1-x N (0≦x≦0.1), the cladding layer of the second conductivity type is made of Al y Ga 1-y N (0≦y≦0.1), and the active layer has a single or multiple quantum well structure composed of a well layer of In w Ga 1-w N (0.06≦w≦0.2) and a barrier layer of In b Ga 1-b N (0.01≦b≦0.05).