| 摘要 |
An optical system includes a light-transmitting substrate having at least two external major surfaces and edges and an optical element for coupling light waves into the substrate, by total internal reflection. At least one partially reflecting surface is located in the substrate for coupling light waves out of the substrate, and at least one transparent layer, having a refractive index substantially lower than the refractive index of the light transmitting substrate is optically attached to at least one of the major surfaces of the substrate, defining an interface plane. The light waves coupled inside the substrate are substantially totally reflected from the interface plane between the major surface of the substrate and the transparent layer. |
