The cladding semiconductor layer 302 as an outer layer for electrode, for example, anode, connection may be disposed on the substrate 100 next to the third III-V optical layer 503 and electrically connected to the III-V optical layer 503. Both the first III-V optical layer 501 and the third III-V optical layer 503 may be used for the outer layers of the edge emitting laser, and the second III-V optical layer 502 having smaller band gap may be used for the inner layer. Thus, there are two junctions (or boundaries), one at each side of the inner layer to form a double heterojunction. The cladding semiconductor layer 302 may include a p-doped semiconductor material, for example, Si doped with boron (B), aluminum (Al), gallium (Ga) and indium (In), and the p-doped semiconductor may be heavily doped such as, for example, p+-Si. Thus, the cladding semiconductor layer 302 is a p-doped cladding semiconductor layer. Other suitable p-doped semiconductors may also be used to form the cladding semiconductor layer 302. The cladding semiconductor layer 302 may include a p-doped amorphous Si. A width of the cladding semiconductor layer 302 in the first direction may be from about 0.5 μm to about 2 μm, and a length of the cladding semiconductor layer in the second direction may be from about 100 μm to about 8000 μm. When the semiconductor structure 301 is n+-Si and the cladding semiconductor layer is p+-Si, both may function as part of waveguide to confine the laser light.