| 摘要 |
A high-efficiency holographic diffuser is provided, the holographic diffuser being comparatively thin, yet characterized by good optical density along a broad bandwidth. In particular, the high-efficiency holographic diffuser comprises a light-transmissive substrate; and a planar hologram layer, the planar hologram layer having an interference pattern holographically recorded therein, the interference pattern producing a diffuse light pattern in reflection when irradiated with light, the interference pattern being resultant of the combination of an incident wavefront and a counterpropagating wavefront substantially coherent with the incident wavefront, the incident coherent wavefront having impinged upon the planar hologram layer from a first side, the counterpropagating coherent wavefront having impinged upon the planar hologram layer from a second side opposite the first side, the incident coherent wavefront being a diffused coherent wavefront, the counterpropagating coherent wavefront also being a diffused coherent wavefront. The high-efficiency holographic diffuser can be formed by diffusing a coherent wavefront prior to its incidence on a holographic recording medium, transmitting the diffused wavefront through the holographic recording medium, then reflecting the transmitted diffused wavefront with a highly reflective optical element back through the holographic recording medium.
|
