Patent ID: 7333523

Claim:
A semiconductor laser device comprising: a first cladding layer of a first conductivity type; an active layer provided on the first cladding layer, the active layer having a single quantum well structure or a multiple quantum well structure of In x Ga 1-x N (0.05≦x≦1) and In y Ga 1-y N (0≦y≦1,x>y); an overflow blocking layer of a second conductivity type provided on the active layer, the over flow blocking layer being made of an Al t Ga 1-t N (0<t≦1) layer; and a second cladding layer of the second conductivity type provided on the over flow blocking layer, the first cladding layer including a superlattice lamination of Al s Ga 1-s N (0<s≦0.3, t>s) and GaN layer, or an Al s Ga 1-s N (0<s≦0.3, t>s) layer, the second cladding layer including a superlattice lamination of Al u Ga 1-u N (0<u≦0.3, t>u) and GaN layer, or an Al u Ga 1-u N (0<u≦0.3, t>u) layer, and the active layer including a region having an impurity concentration of 3×10 17 cm −3 or more and having a thickness of 30 nm or less between the overflow blocking layer and a well layer in the active layer closest to the overflow blocking layer.