Abstract: A self-aligned type semiconductor laser device which is capable of oscillation at high optical output, scarcely develops COMD, and maintains high reliability for a long term. The SAS type semiconductor laser device has an active layer, and a low refractive-index layer formed close the active layer and functioning also as a current blocking layer. The low refractive-index layer includes a plurality of compound semiconductor layers made of AlxGa1−xAs (0≦x≦1), and the compound semiconductor layers have refractive indices thereof set such that the refractive index lowers with increasing distance from the active layer. Specifically, the low refractive-index layer includes a plurality of AlGaAs layers, and the AlGaAs layers have contents of Al thereof set such that the content of Al increases with increasing distance from the active layer.