Semiconductor laser with improved window structure

Abstract

A semiconductor laser includes a compound semiconductor substrate of a first conductivity type; successively disposed on said semiconductor substrate, a first conductivity type lower cladding layer, an active layer including a multiple quantum well structure, first and second upper cladding layers of a second conductivity type opposite the first conductivity type, and a first contacting layer of the second conductivity type in electrical contact with the second upper cladding layer; first and second electrodes in electrical contact with the semiconductor substrate and the first contacting layer, respectively, the semiconductor laser including opposed facets transverse to the lower cladding and the first and second upper cladding layers, the second upper cladding layer having a ridge shape that extends between the facets of the semiconductor laser and is centrally disposed on the first upper cladding layer; a first conductivity type current blocking layer disposed on and between the first upper cladding layer and the first contacting layer, contacting opposite sides of the ridge, and extending between the facets; and a window structure contiguous with each of the facets, each window structure comprising a region including a dopant impurity, each region being disposed within parts of the lower cladding layer, the active layer, and the first upper cladding layer opposite the ridge but not extending substantially into the second upper cladding layer, the multiple quantum well structure of the active layer being disordered in each window region.