INORGANIC MATERIALS FOR ARCHIVAL HOLOGRAPHIC RECORDING

Inorganic material systems for archival holographic recording are cons idered. The emphasis is on bleached silver halide emulsions and CdS an d Se colloidal solutions. The bleached silver halide emulsions were in vestigated to determine the salient parameters that influence photolyt ic stability and diffraction efficiency. The experimental and theoreti cal investigations reveal that the silver halide grains, the gelatin m atrix, and the gelatin matrix voids are contributing to the holographi c storage mechanism. By the adsorption of bromine from the processing solutions on the silver halide grains, it is possible to extend the ph otolytic stability almost indefinitely. By suppressing the influence o f the gelatin matrix and the gelatin matrix voids by chemical processi ng, it is possible to obtain increased diffraction efficiencies reachi ng 70%. The colloidal solutions were investigated to determine the bas ic mechanisms for photodepositing ultrathin surface relief holographic gratings. The results reveal that the photodeposition includes primar y photoreduction and secondary adsorption controlled processes. A mode l is developed to predict the spatial frequency response of the colloi dal solutions showing that the recorded spatial resolution is limited by the particle sizes.