Diffusion parameters estimation of holographic memories based in PVA/acrylamide photopolymer

Abstract

The hard research about the models to predict and understand the behaviour of photopolymers have as a results many interesting works for 2-dimensional cases. These studies permits obtain the mains parameters that governs the process in photopolymers with maximum thickness about 200 μm. Historically this materials, dry layers of photopolymers, have been used in many attractive devices and now a new application of this type of material is being developed: the application of photopolymers as holographic memories. The main characteristics of these layers of photopolymers are their high thickness (higher than 600 μm). In order to optimize this layers the original photopolymer composition has been changed, then a new parameters estimation has be done. In this work this study is made using PVA/Acrylamide photopolymer with layers around 800 μm of thick. The values of monomer and polymer diffusion are obtained and the values of polymerization rate constant and residual monomer are calculated too using and first harmonic diffusion constant. The validity of this model to study the layers with high thickness is evaluated, because this type of materials only a few percent of the initial light arrive to the depth zones of photopolymer.