Method of constructing a hologram whose thickness is independent of the thickness of the holographic recording material

摘要

A method of constructing flare-free reflection holograms uses a light scattering mechanism positioned between a first exposure beam and holographic recording material to remove the spatial coherence from all but adjacent rays within a relatively small angular range before the light rays of the first exposure beam strike the hologram surface. A second exposure beam of spatially coherent light rays interferes with mutually spatially coherent light rays of the first exposure beam to form a primary hologram. Light rays reflected off the holographic recording material noncontacting surface of the substrate interfere with the light rays of the first exposure beam but do not form parasitic hologram recordings because the interfering light rays are not mutually spatially coherent. The size of the region on the scattering device illuminated by the first exposure beam can also be selectively adjusted to determine the angular range of spatial coherence of the exposure beam and thereby create a primary hologram whose thickness is independent of and, if desired, may be made less than the thickness of the holographic recording material.