Patent ID: 7145930

Claim:
A semiconductor laser device formed on a semiconductor substrate, the laser device comprising: a lower cladding layer having an n type conductivity, formed on a top side of said substrate, said lower cladding layer including a first GRIN-SCH layer; an active layer formed on a top side of said lower cladding layer; an upper cladding layer having a p type conductivity, formed on a top side of said active layer, said upper cladding layer including a second GRIN-SCH layer; a mesa structure formed by said lower cladding layer, said active layer and said upper cladding layer; a first current confinement layer having a p type conductivity, formed at a side of the mesa structure and contacting the lower cladding layer; and a second current confinement layer having an n type conductivity, formed at a side of the mesa structure and on a top side of and in contact with said first current confinement layer, wherein the closest distance between the second current-confinement layer and the active layer has a value in the range from 0.15 μm to 0.6 μm.