Patent ID: 7359417

Claim:
A semiconductor laser comprising: an n-type clad layer; a p-type clad layer; an active layer sandwiched by said n-type clad layer and said p-type clad layer; a current constriction layer, formed in either of said n-type and p-type clad layers, in which a stripe trench is formed, said current constriction layer having a different conductivity type from said clad layer; and a light confinement layer formed between said active layer and said current constriction layer and having a smaller refractive index than said clad layer, wherein said light confinement layer is formed to have a non-doped type or the same conductivity type as said clad layer in which said light confinement layer is provided, wherein said current constriction layer is formed of a semiconductor layer having the same refractive index as said light confinement layer, and wherein said light confinement layer is formed to have a thickness of 0.05-0.3 μm and said current constriction layer is formed to have a thickness of 0.2-0.5 μm.