Patent ID: 6195373
Filing Date: 2001-02-27
Classification: H01S

Abstract:
An index optical waveguide semiconductor laser comprising a lower clad layer, a lower optical waveguide layer, an active layer, an upper optical waveguide layer and an upper clad layer superposed one on another in this order on a GaAs substrate, wherein the improvement comprises thateach of the upper and lower clad layers and the upper and lower optical waveguide layers is of a composition which matches with the GaAs substrate in lattice,the upper optical waveguide layer comprises an In.sub.x2 (Al.sub.z2 Ga.sub.1-z2).sub.1-x2 As.sub.1-y2 P.sub.y2 (1.gtoreq.y2.gtoreq.0.8) optical waveguide layer and a Ga.sub.1-z1 Al.sub.z1 As optical waveguide layer formed on the upper surface of the In.sub.x2 (Al.sub.z2 Ga.sub.1-z2).sub.1-x2 Ax.sub.1-y2 P.sub.y2 optical waveguide layer, andthe difference in the refractive index to light at the oscillation wavelength of the semiconductor laser between the In.sub.x2 (Al.sub.z2 Ga.sub.1-z2).sub.1-x2 As.sub.1-y2 P.sub.y2 optical waveguide layer and the Ga.sub.1-z1 Al.sub.z1 As optical waveguide layer is not larger than 2% of the larger of the refractive indexes of the optical waveguide layers.