Three-dimensional extended nonlocal photopolymerization driven diffusion model. Part I. Absorption

When holographic gratings are recorded in a photopolymer material layer, the spatial distributions of the photoreactions taking place lead to the formation of nonuniform gratings in depth. In an effort to study such effects, in this series of papers a three-dimensional (3D) nonlocal photopolymerization driven diffusion (NPDD) model is developed. In Part I, we focused on describing the photoinitiation mechanisms by introducing a 3D dye absorption model that more accurately and physically describes the processes taking place. Then, the values of physical parameters are extracted by numerically fitting experimentally obtained normalized transmittance growth curves for a range of layer thicknesses in an acrylamide/polyvinyl alcohol (AA/PVA) photopolymer material sensitized by Erythrosine B (EB). In Part II [J. Opt. Soc. Am. B 31, 2648 (2014)], applying the results in Part I, the full 3D photophysical and photochemical evolutions are modeled. Then the resulting 3D NPDD model is validated experimentally. (C) 2014 Optical Society of America