SEMICONDUCTOR LASER DEVICE, ITS MANUFACTURE, AND OPTICAL COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To make the spectral line width of a semiconductor laser device easily narrowed. SOLUTION: A mesa-like stripe area 31 is constituted by successively forming an n-type InGaAsP waveguide layer 12 having a thickness of 500 nm, a multilayered heterojunction superlattice layer 13 which works as such a carrier selecting layer that only selectively passes electrons having prescribed energy among injected carriers, a multilayer quantum well active layer 14, a p-type InGaAsP waveguide layer 15 having a thickness of 50 nm, and a p-type InP clad layer 16 from a substrate side. The superlattice layer 13 is constituted in a multilayered quantum well layer in which pairs of InGaAsP well layers 13w having a thickness of 6 nm and a compositional wavelengthλg of 40μm and InGaAsP barrier layers 13b having a thickness of 6 nm and a compositional wavelengthλg of 1.15μm are laminated upon another.