Double heterojunction semiconductor laser having improved light confinement

摘要

A double heterojunction semiconductor laser includes a semiconductor substrate of a first semiconductor material having a first conductivity type; successively disposed on the semiconductor substrate, a first cladding layer of the first conductivity type, an active layer, and a second cladding layer of a second conductivity type, opposite the first conductivity type, the second cladding layer having a central ridge including side surfaces and a top surface; a current blocking layer of the first conductivity type disposed on the second cladding layer and contacting the side surfaces of the ridge; a second conductivity type contact layer of the first semiconductor material disposed on the top surface of the ridge and on the current blocking layer; and first and second electrodes contacting the semiconductor substrate and the contact layer, respectively, wherein at least one of the first and second cladding layers is a superlattice layer including a plurality of alternating layers of different compositions, the superlattice layer lattice matching with the first semiconductor material.