Structure of VCSEL and method for manufacturing the same

The invention refers to a Vertical-Cavity Surface-Emitting Laser (VCSEL) having a novel three-trenches structure. By forming a first trench within a mesa around the periphery of an output window of the VCSEL, the overall capacitance is decreased and the time used in the oxidation process for an oxidation layer is shortened. By forming a second trench and a third trench on the periphery of the mesa in a step-like concave manner, the mesa becomes a step-like structure having double mesa-layers. Such that, a larger heat-radiating area can be obtained for decreasing thermal effects, while the metal-gap defects of the metal layer can also be avoided. An implant layer is formed around the periphery of the output window for controlling the modal and constraining the currents, in addition, an output layer is formed on the output window for controlling the output light.