Patent ID: 8175128

Claim:
A semiconductor laser element comprising: a first semiconductor layer; an active layer having a current injection region; a second semiconductor layer; a third semiconductor layer; and an electrode for injecting a current into the active layer, wherein the first semiconductor layer, the active layer, the second semiconductor layer, and the third semiconductor layer are laminated in that order on a substrate, the first semiconductor layer has a current constriction layer which constricts the current injection region of the active layer, the current constriction layer having a doping other than that of a portion of the first semiconductor layer further from the substrate than the current constriction layer, said current constriction layer having an opening portion with a predetermined width in a region corresponding to the current injection region of the active layer such that during operation a current passing through the opening portion is injected into the current injection region of the active layer, the third semiconductor layer is formed on an upper surface of the second semiconductor layer in a region corresponding to the current injection region of the active layer, and the electrode is formed on the upper surface of the second semiconductor layer in a region other than that of the third semiconductor layer.