Patent ID: 7474682

Claim:
A semiconductor laser device including a semiconductor laser element having a ridge type cladding layer, on a semiconductor substrate, said semiconductor laser element comprising: a resonator for performing laser oscillation due to injection of carriers, the resonator having different reflectivities at a front facet and a rear facet, the front facet and the rear facet being arranged on opposite sides of the resonator; a stripe structure for injecting carriers into the resonator, extending in an axis direction of the resonator; and an electrode disposed on an upper portion of the stripe structure, wherein said electrode is divided into two or more parts so that plural electrode parts are arranged along the resonator axis direction, wherein, among the plural electrode parts, a current is to be injected into an electrode part that is positioned in the vicinity of the front facet of the resonator from which laser light is emitted, so as to obtain a larger current density in an active layer of the electrode part as compared with a current density in an electrode part that is positioned in the vicinity of the rear facet of the resonator, and wherein said stripe structure has a taper shape in which a stripe width at the front facet of the resonator from which laser light is emitted is larger than a stripe width at the rear facet.