Analytical form for holographic contrast growth in photorefractive polymers

Abstract

An analytical form for holographic contrast growth in photorefractive polymer composites under constant illumination is presented. The transient is a convolution of the exponential growth of the space-charge field and the rotational response of the chromophores in the amorphous host. Under this formalism, the contrast growth is fully characterised by just two parameters: the rise time of the space-charge field and the rotational diffusion constant of the material. There is excellent agreement between theory and experiment. Using this description of holographic index growth, the reciprocal relationship between rise time and intensity is confirmed.