Semiconductor laser device in which near-edge portion of upper cladding layer is insulated for preventing current injection

In a semiconductor laser device: a p-type Al_zGa_1-zAs cladding layer is formed above an active layer, where z0.3; a p-type GaAs contact layer is formed on the cladding layer except for at least one near-edge portion of the cladding layer; and an electrode is formed on at least the contact layer. The upper surface of each of the at least one near-edge portion of the cladding layer is insulated, where each of the at least one near-edge portion of the cladding layer is located in a vicinity of one of opposite end facets perpendicular to the direction of laser emission.