Modeling the photochemical kinetics induced by holographic exposures in PQ/PMMA photopolymer material

Abstract

Phenanthrenequinone (PQ) doped poly(methyl methacrylate) (PMMA) photopolymer material is receiving ever greater attention in the literature due to its attractive properties for applications such as holographic data storage, hybrid optoelectronics, solar concentrators, self-trapping of light, and diffractive optical elements. PQ/PMMA photopolymer material can be used to produce three-dimensional low loss, low shrinkage recordings that are environmentally stable, have high contrast refractive index variations, and can produce high-optical-quality devices. However, in any attempt to further develop the potential of such materials, a more physical and accurate theoretical model has become ever more necessary and important. In this paper, based on a detailed analysis of the photochemical mechanisms present in PQ/PMMA photopolymer during holographic grating formation, a set of rate equations are derived governing the temporal and spatial variations of each associated chemical species concentration. Experimental results are presented, which are then fit using this model. In this way, values for several kinetic parameters are estimated and their significance is discussed.