Patent ID: 7924898

Claim:
A nitride based semiconductor laser device comprising: a nitride based semiconductor layer having an optical waveguide extending in a substantial [0001] direction and having one facet composed of a substantial (0001) plane and the other facet composed of a substantial (000-1) plane as a pair of cavity facets; a first protective film provided on said one facet and including oxygen as a constituent element; and a second protective film provided on said other facet and including nitrogen as a constituent element, wherein the intensity of laser light emitted from said one facet is higher than the intensity of laser light emitted from said other facet, said first protective film further includes nitrogen as a constituent element, the first protective film's oxygen composition ratio being higher than the nitrogen composition ratio, and said second protective film further includes oxygen as a constituent element, the second protective film's nitrogen composition ratio being higher than the oxygen composition ratio.