Patent ID: 7123641

Claim:
A semiconductor laser device comprising: a GaAs substrate; an InGaAsP quantum well active layer supported on the GaAs substrate, said quantum well active layer being composed of one or a plurality of well layers and a plurality of barrier layers alternately disposed; an n-type cladding layer and a p-type cladding layer, which are provided in a manner so as to interpose the quantum well active layer therebetween; a first guide layer provided between the n-type cladding layer and the quantum well active layer; and a second guide layer provided between the p-type cladding layer and the quantum well active layer, wherein said semiconductor laser device has an oscillation wavelength of larger than 760 nm and smaller than 800 nm, wherein the first guide layer is formed of InGaP, and wherein the second guide layer is formed of AlGaAs and is in contact with the p-type cladding layer and the quantum well active layer.