Patent ID: 7492801

Claim:
A semiconductor laser element comprising: a semiconductor substrate of first conductivity type; a lower cladding layer of first conductivity type, an active layer, a first upper cladding layer of second conductivity type, and a second upper cladding layer of second conductivity type, which are stacked in this order on the semiconductor substrate; a third upper cladding layer of second conductivity type and a contact layer of second conductivity type, which are formed directly or via a semiconductor layer of second conductivity type on the second upper cladding layer and constitute a stripe-shaped ridge structure; and an electrode layer, wherein a second-conductivity-type doping concentration of the second upper cladding layer is lower than second-conductivity-type doping concentrations of the first upper cladding layer and the third upper cladding layer and is not higher than 1×10 17 cm −3; a sum total of a layer thickness of the first upper cladding layer and a layer thickness of the second upper cladding layer is 0.3 m-1.5 μm, inclusive, and the electrode layer forms an ohmic junction with the contact layer, and the electrode layer forms a Schottky junction with at least part of the second upper cladding layer located beside the ridge structure when the electrode layer is directly formed on the second upper cladding layer, and when the electrode layer is formed on the second upper cladding layer via the semiconductor layer of second conductivity type, the electrode layer forms a Schottky junction with at least part of the semiconductor layer of second conductivity type located beside the ridge structure.