InGaAsP semiconductor laser device in which near-edge portions are filled with non-absorbent layer, and lower optical waveguide layer includes InGaP intermediate layer

摘要

In a process for producing a semiconductor laser device, an n-type cladding layer, an n-type or i-type In_x2Ga_1−x2As_1−y2P_y2 first lower optical waveguide layer, an i-type In_x5Ga_1−x5P intermediate layer, an i-type In_x2Ga_1−x2As_1−y2P_y2 second lower optical waveguide layer, an In_x1Ga_1−x1As_1−y1P_y1 compressive strain active layer, a p-type or i-type In_x2Ga_1−x2As_1−y2P_y2 first upper optical waveguide layer, and an In_x5Ga_1−x5P cap layer are formed on an n-type GaAs substrate. Then, near-edge portions of the cap layer are etched off with a hydrochloric acid etchant, and near-edge portions of the active region above the intermediate layer are etched off with a sulfuric acid etchant so as to produce spaces in vicinities of end facets. Next, the spaces are filled with a p-type In_x2Ga_1−x2As_1−y2P_y2 second upper optical waveguide layer formed over the cap layer, and a p-type upper cladding layer is formed on the second upper optical waveguide layer.