According to an exemplary embodiment of the present invention, a method for manufacturing edge emitting lasers may include the following steps: providing a semiconductor substrate; forming a hard mask layer on top of the semiconductor substrate, the hard mask layer arranged in a first direction, and extending in a second direction; etching the semiconductor substrate using the hard mask layer as an etching mask to form a semiconductor structure protruding above the semiconductor substrate in a third direction, perpendicular to the first and second directions; forming a first dielectric layer over the semiconductor substrate, the first dielectric layer having a top surface lower than a top surface of the semiconductor structure, so as to expose sidewalls of the semiconductor structure above the first dielectric layer; implanting n-dopant to the semiconductor structure to form n-doped semiconductor in the semiconductor structure; laterally growing a first III-V optical layer, a second III-V optical layer and a third III-V optical layer sequentially on and from each of the exposed sidewalls of the semiconductor structure, the first, second and third III-V optical layers extending in the second direction; forming p-doped cladding semiconductor layers directly connected to exposed sidewalls of the third III-V optical layers and extending in the second direction; forming a second dielectric layer to cover the first dielectric layer, the hard mask layer, the semiconductor structure, the p-doped cladding semiconductor layer, and the first, second and third III-V optical layers; and forming a first contact structure through the second dielectric layer and the hard mask layer to connect the semiconductor structure, and second contact structures through the second dielectric layer to connect the p-doped cladding semiconductor layers. The sequence of the steps as described above is preferred. However, the invention is not limited to the performance of these steps with the sequence or order presented above. Many steps may also be applied to the semiconductor substrate before, between or after the steps shown above. FIG. 2 is a flow chart of a method for making edge emitting lasers on a semiconductor substrate according to an exemplary embodiment of the present invention. FIGS. 3A-7A and FIGS. 3B-7B are demonstrative illustrations of cross-sectional views or top views of structures in the method of manufacturing the edge emitting laser according to an exemplary embodiment of the present invention.