Abstract: A semiconductor laser has a substrate having a strip raised region on a principal surface thereof which comprises a {100} face, the strip raised region extending along a <011> axis. First lower and second upper cladding layers are disposed on the substrate, and an active layer is interposed between the first and second cladding layers. The first and second cladding layers and the active layers are divided into sections in a cross-sectionally triangular body and sections on opposite sides of the cross-sectionally triangular body, by two slant surfaces extending from opposite edges of the raised region and intersecting with each other above the raised region. The semiconductor laser also includes a current blocking layer disposed on each side of the cross-sectionally triangular body, a third cladding layer covering the current blocking layer and the cross-sectionally triangular body, and a cap layer disposed on the third cladding layer.