Patent ID: 6888870

Claim:
A semiconductor laser of a ridge-type current confinement structure, comprising a first conduction-type cladding layer, a second conduction-type cladding layer, and an active layer that is sandwiched between these cladding layers, on a first conduction-type semiconductor substrate, wherein the second conduction-type cladding layer has mesa-type stripe-shaped recessed portions in at least four spots, so as to form a central ridge portion, which constitutes a ridge-type current confinement portion, and two or more lateral ridge portions of a height larger than that of the central ridge portion, which are positioned on both sides of the central ridge portion, and which include the second conduction-type cladding layer, wherein an insulation film with a lower refractive index than the second conduction-type cladding layer is formed into a pair of stripes disposed respectively in the regions from the side surface of the second conduction-type cladding layer on both side portions of the central ridge portion toward the outside, the insulation film not being formed on the central ridge portion, and wherein a current blocking layer is formed above the second conduction-type cladding layer of each of the lateral ridge portions.