DCG holograms as nanosized composite film elements

Abstract

It is well known that dichromated gelatin is one of the best materials for phase hologram recording. Several competing hypotheses for the nature ofthe photoinduced response in DCG have been discussed in the literature, and still there is no generally accepted point of view. Recently we have demonstrated how the optical response of DCG holograms can be analyzed on the basis of light scattering from nano-voids, which appear in the process of hologram formation. We have assumed that the voids are ellipsoids with dimensions of 10 - 40 nm, i.e. we are within the approximations of Raleigh scattering. Here, we analyze the DCG reflection hologram performance in terms of rigorous theory of light scattering with no limitations for the size of the voids. Mathematical simulations of the reflection spectra give a plausible quantitative explanation of many experimental facts related to DCG holograms obtained by the so-called 'drastic' chemical treatment after exposure.