Patent ID: 7706423

Claim:
A dual-wavelength semiconductor laser device comprising: a substrate; a first semiconductor laser element including a first clad layer of a first conductivity type formed over the substrate, a second clad layer of a second conductivity type formed above the first clad layer, a first active layer formed between the first clad layer and the second clad layer, a first etching stopper formed on the second clad layer, and a third clad layer of the second conductivity type formed on the first etching stopper; and a second semiconductor laser element including a fourth clad layer of the first conductivity type formed over the substrate, a fifth clad layer of the second conductivity type formed above the fourth clad layer, a second active layer formed between the fourth clad layer and the fifth clad layer, the second active layer generating light having a wavelength shorter than the wavelength of light generated by the first active layer, a second etching stopper formed on the fifth clad layer, and a sixth clad layer of the second conductivity type formed on the second etching stopper, wherein the first etching stopper is made of a material which allows diffusion of impurities less easily than a material forming the second etching stopper, and the second clad layer and the fifth clad layer are made of (Al a Ga 1-a ) b In 1-b P(0≦a≦1, 0≦b≦1).