Phase holograms formed by silver halide (sensitized) gelatin processing

Abstract

A novel recording process for the formation of phase volume holograms at up to 1500 cycles/mm is described. The term silver halide (sensitized) gelatin or SHG denotes an all-gelatin phase material, which records the initial image information through photon absorption by the silver halide. Our process uses a reversal bleach that dissolves the developed silver image and cross-links the gelatin molecules in the vicinity of the developed image. Experiments have determined the stored image as refractive-index differences within the remaining gelatin. The major attributes of SHG holograms are (1) panchromatic response, (2) 100:1 greater light sensitivity than dichromate (sensitized) gelatin, and (3) elimination of darkening (printout) effects.

Silver halide sensitized gelatin derived from BB-640 holographic emulsion

“…This technique was initially developed by Pennington and Harper, 3 although the technique in its present state is the result of a study done by Graver et al 4 on the one hand and by Chang and Winick 5 on the other. Ferrante 6 studied the modulation transfer function closely and achieved a significant decrease in diffraction efficiency at 2000 lines mm…”

Optimized spatial frequency response in silver halide sensitized gelatin

“…Thus an increase in the temperature of the bleach can modify the hardening bias level of the photographic emulsion. 11 Graver et al 12 have discussed the possible photochemical process that is produced by this process. However, there are some differences between the process presented by Graver and the method that we propose.…”

Hybrid process of latent image formation in silver halide sensitized gelatin: differential hardening with microvoids

“…On the one hand, refractive-index modulation due to a hardness di erential generates part of the di raction e ciency [4,5] and, on the other, the formation of microvoids inside the gelatin results in an increase in the modulation capacity of the latent image [6]. Both models have been studied and analysed from an experimental point of view, with physical evidence in the case of microvoids in re¯ection gratings obtained with the Russian PFG-03 emulsion (precursor of the present Slavich emulsions) by Usanov and Shevtsov [7] and in transmission gratings obtained with the Slavich VR-P plates by Kim et al [8] In this study we aim to review both models of image formation, showing that they are not incompatible and may be combined in order to explain the experimental results.…”