Patent ID: 8638829

Claim:
A semiconductor laser comprising: a columnar lamination structure including a first multi-layer reflection mirror, a lower spacer layer, an Al x Ga y In 1-x-y P (where 0≦x<1 and 0<y<1) based active layer, an upper spacer layer, a second multi-layer reflection mirror, and a lateral mode adjusting layer on a substrate in this order from the substrate and including a current narrowing layer, wherein the current narrowing layer includes an unoxidized region in an in-plane central region and a circular oxidized region in the circumference of the unoxidized region, wherein the lateral mode adjusting layer includes a high reflection region to correspond to the unoxidized region and a circular low reflection region in the circumference of the high reflection region, wherein the high reflection region is formed by a structure in which a first adjusting layer, of which a thickness is (2α−1)λ/4n 1 (where α is an integer equal to or larger than 1, λ is an oscillation wavelength, and n 1 is a refractive index) and the refractive index n 1 is lower than that of the surface of the first multi-layer reflection mirror, and a second adjusting layer, of which a thickness is (2β−1)λ/4n 2 (where β is an integer equal to or larger than 1 and n 2 is a refractive index) and the refractive index n 2 is higher than that of the first adjusting layer, are laminated in this order, wherein the low reflection region is formed by a third adjusting layer of which a thickness is (2γ−1)λ/4n 3 (where γ is an integer equal to or larger than 1 and n 3 is a refractive index) and the refractive index n 3 is higher than that of the first adjusting layer, and wherein the second multi-layer reflection mirror is formed by alternately laminating a low refractive index layer and a high refractive index layer, the uppermost layer of the second multi-layer reflection mirror is a high refractive index layer and the lowermost layer of the second multi-layer reflection mirror is a high refractive index layer, and the current narrowing layer is formed in a low refractive index layer of the second multi-layer reflection mirror.