Abstract: An embodiment of semiconductor laser comprising: (a) a GaN, AlGaN, InGaN, or AlN substrate; (b) an n-doped cladding layer situated over the substrate; (c) a p-doped cladding layer situated over the n-doped; (d) at least one active layer situated between the n-doped and the p-doped cladding layer, and at least one of said cladding layers comprises a superstructure structure of AlInGaN/GaN, AlInGaN/AlGaN, AlInGaN//InGaN or AlInGaN/AlN with the composition such that the total of lattice mismatch strain of the whole structure does not exceed 40 nm %.

Abstract: Laser diodes and methods of fabricating laser diodes are disclosed. A laser diode includes a substrate including (Al,In)GaN, an n-side cladding layer including (Al,In)GaN having an n-type conductivity, an n-side waveguide layer including (Al,In)GaN having an n-type conductivity, an active region, a p-side waveguide layer including (Al,In)GaN having a p-type conductivity, a p-side cladding layer including (Al,In)GaN having a p-type conductivity, and a laser cavity formed by cleaved facets. The substrate includes a crystal structure having a surface plane orientation within about 10 degrees of a 20 23 or a 20 23 crystallographic plane orientation. The laser cavity is formed by cleaved facets that have an orientation corresponding to a nonpolar plane of the crystal structure of the substrate.