Two-dimensional simulation of holographic data storage medium for multiplexed recording

In this paper, we propose a new analysis model for photopolymer recording processes that calculate the two-dimensional refractive index distribution of multiplexed holograms. For the simulation of the photopolymer medium, two different process must be considered for the determination of the refractive index, i.e. variations of the monomer and polymer distribution in the medium during exposure and after exposure. There variations are related to the polymerization reaction ( conversion of the monomer to polymer, propagation of the living chains and termination), as also the diffusion of the monomer related to the concentration gradients taking place during inhomogeneous irradiation. By evaluating the refractive index pattern on each layer, the diffraction beams from the multiplexed hologram can be read out by beam propagation method (BPM). This is the first paper to determine the diffraction beam from a multiplexed hologram in a simulated photopolymer medium process. We analyze the time response of the multiplexed hologram recording processes in the photopolymer, and estimate the degradation of diffraction efficiency with multiplexed recording. This work can greatly contribute to understanding the process of hologram recording. (c) 2008 Optical Society of America.