Patent ID: 6292502
Filing Date: 2001-09-18
Classification: B82Y,H01S

Abstract:
A semiconductor laser device comprising:a GaAs substrate of a first conductive type;at least one In.sub.0.5 (Ga.sub.1-x Al.sub.x).sub.0.5 P cladding layer of the first conductive type, which is provided on a first principal plate of said GaAs substrate;a plurality of well layers provided on said cladding layer of the first conductive type;a plurality of In.sub.0.5 (Ga.sub.1-y Al.sub.y).sub.0.y P barrier layers associated with said plurality of well layers for forming a multiple quantum well structure, each of said plurality of In.sub.0.5 (Ga.sub.1-y Aly.sub.y).sub.0.5 P barrier layers being provided between adjacent well layers of said plurality of well layers;at least one first In.sub.0.5 (Ga.sub.1-y Al.sub.y).sub.0.5 P guiding layer, which is provided between said cladding layer of the first conductive type and said multiple quantum well structure;at least one In.sub.0.5 (Ga.sub.1-x Al.sub.x).sub.0.5 P cladding layer of a second conductive type, which is provided on said multiple quantum well structure,at least one second In.sub.0.5 (Ga.sub.1-y Al.sub.y).sub.0.5 P guiding layer, which is provided between said multiple quantum well and said cladding layer of the second conductive type;wherein Al composition ratios of said cladding layers of the first and second conductive types are greater than Al composition ratios of said first and second guiding layers (x>y),wherein a compressive strain is introduced into said well layers, said multiple quantum well structure produces a light having a wavelength of 650.+-.20 nm, and said well layers have a thickness of less than 6 nm, andwherein a tensile strain for compensating said compressive strain in said well layers is introduced into at least one of said first guiding layer, said second guiding layer and said barrier layers wherein at least one of said cladding layer of the first conductive type and said cladding layer of the second conductive type has a second cladding layer of an In.sub.0.5 (Ga.sub.1-z Al.sub.z).sub.0.5 P on a side near said multiple quantum well structure, and Al composition ratio of said second cladding layers is greater than Al composition ratios of said cladding layers of the first and second conductive types (z>x).