NOISE SOURCES IN SILVER-HALIDE VOLUME DIFFUSE-OBJECT HOLOGRAMS

Dichromated gelatin has been established as the most frequently used r ecording material for the production of holographic optical elements. New applications are being found for photopolymers in previously unexp lored areas such as holographic interconnect systems, However, photogr aphic emulsion from the beginning has been and continues to be the mos t used holographic recording material. This is due to its relatively h igh sensitivity and ease of processing, the availability of improved p rocessing chemistries and commercial films, and the repeatibility of t he results. We analyze different sources of noise in photographic emul sions (such as intermodulation noise, noise gratings, and nonlinear no ise) and the influence of the photochemical process on those noise sou rces. Bleached emulsions using rehalogenating and solvent processes ar e considered, and silver-halide-sensitized gelatin is discussed as a m edium for transmission holograms. New developers and new noise models are presented on the supposition that the nonlinear response of the re cording material is due to the photochemical process.