Patent ID: 7616673

Claim:
A semiconductor laser device comprising: a semiconductor laser body including a resonator and having a front end face and a rear end face facing each other, said resonator being located between said front and rear end faces, said front end face emitting principal laser light; a reflectance control film located on said front end face of said semiconductor body and including a first dielectric film having a first thermal conductivity; and a surface protective film located on said first dielectric film of said reflectance control film, with said reflectance control film located between said front end face and said surface protective film, said surface protective film having a thickness of no more than 20 nm, having a second thermal conductivity, different from the first thermal conductivity, being a material selected from the group consisting of silicon oxide, zirconium oxide, tantalum oxide, niobium oxide, and hafnium oxide, and being outermost of said films coating said front end face of said semiconductor laser.