Patent ID: 7542500

Claim:
A semiconductor laser device comprising: a first light emitting portion and a second light emitting portion provided on a substrate and having the same resonator length L, wherein each of said first light emitting portion and said second light emitting portion includes a first cladding layer of a first conductivity type, an active layer provided on said first cladding layer and a second cladding layer of a second conductivity type provided on said active layer, and has a stripe structure for injecting carriers, said stripe structure of said first light emitting portion has a section having a width changing along a resonator direction and includes a first front end face, the following relationships hold: W f1 ≧W 1 ; W 1 >W 2 ; and ( W f1 −W 1 )/2 L 1 <( W 1 −W 2 )/2 L 2 wherein W f1 is a width of said stripe structure on said first front end face; W 1 is a width of said stripe structure in a position away from said first front end face by a distance L 1 ; and W 2 is a width of said stripe structure in a position away from said first front end face by a distance L 1 +L 2 (whereas L 1 +L 2 ≦L), said stripe structure of said second light emitting portion has a section having a width changing along a resonator direction and includes a second front end face, and the following relationships hold: W f2 ≧W 3 ; W 3 >W 4 ; and ( W f2 −W 3 )/2 L 3 <( W 3 −W 4 )/2 L 4 , wherein W f2 is a width of said stripe structure on said second front end face; W 1 is a width of said stripe structure in a position away from said second front end face by a distance L 3 (whereas L 1 ≠L 3 ); and W 4 is a width of said stripe structure in a position away from said second front end face by a distance L 3 +L 4 (whereas L 3 +L 4 ≦L).