Patent ID: 8362505

Claim:
An optical device, comprising: a substrate; a plurality of multi-layer structures abutted on said substrate and arranged separately from each other on the substrate, wherein each of the multi-layer structures is consisting of more than two insulating layers, and the refractive indices of the more than two insulating layers are consecutively increasing from a lowermost insulating layer to an uppermost insulating layer; a buffer layer abutted on said multi-layer structures, so that said multi-layer structures are disposed between the buffer layer and the substrate, wherein the buffer layer is formed of semiconductor material; a first conductive semiconductor layer disposed on the buffer layer, wherein the buffer layer is disposed between said multi-layer structures and said first conductive semiconductor layer; an active layer disposed on said first conductive semiconductor layer; a second conductive semiconductor layer disposed on said active layer; and a transparent conductive layer disposed on said second conductive semiconductor layer.