SEMICONDUCTOR LASER DEVICE

摘要

A semiconductor laser element (30) comprises an n-type GaAs substrate (32) having a band gap energy of Eg1, on which are epitaxially grown an n-type AlGaAs cladding layer (34), an active layer (36) formed as a 2-layer quantum - well structure of InGaAs and GaAs and having a band gap energy of Eg2 smalle r than Eg1, a p-type AlGaAs cladding layer (38), and a p-type GaAs cap layer (40). The cap layer and the p-type cladding layer have stripe mesa structure s. Passivation film (42) of SiN is formed in the areas except on the cap layer, and a p-side electrode (44) is formed on exposed part of the cap layer and t he passivation film. An n-side electrode (46) consisting of a metal laminate of In/AuGe/Ni/Au is formed on the back of the substrate, and an InGaAs layer (4 8) lies as an absorber medium between the GaAs substrate and the n-type electro de.