Nonlocal polymerization driven diffusion model: volume changes during grating formation

摘要

Incorporating the effects of volume changes into the Nonlocal Polymerization Driven Diffusion Model we examine these effects on grating evolution. The concept of free volume or hole formation is explored and the subsequent decay and diffusion of holes examined. The inclusion of a nonlocal temporal response function is also shown to be critical to the modeling of grating formation for short recording times. The model is solved using a finite difference technique and results converted initially to refractive index modulation and then to diffraction efficiency using rigorous electromagnetic theory. Fits are carried out to experimental data and model parameters determined.