Patent ID: 7039085

Claim:
A semiconductor laser device comprising: a semiconductor body including a semiconductor substrate supporting a plurality of semiconductor layers, the semiconductor layers including an active layer in which light having a characteristic wavelength is generated, a pair of cladding layers disposed on opposite sides of the active layer, and opposed front and rear end faces transverse to the substrate and semiconductor layers, the light generated within the semiconductor laser exiting through the front end face and being reflected from the rear end face; a film on the front end face and having a first, relatively low reflectivity at the characteristic wavelength; and a dielectric multilayer film on the rear end face and having a second reflectivity, higher than the first reflectivity, and at least 40% at the characteristic wavelength, wherein the dielectric multilayer film includes a film of aluminum oxide in contact with the rear end face, a film of silicon oxides, and a film of tantalum oxide.