Investigation on mechanism of multiple holographic recording with uniform diffraction efficiency in photopolymers

In this paper, our simplified model for grating formation in photopolymers is extended to describe the effects of uniform post-exposure on an existing hologram, and further to present a new model of holographic multiplexing for calculating the exposure schedule for multiplexed gratings with uniform diffraction efficiency. It is experimentally verified that the refractive-index modulation of the existing gratings continues to increase when a current grating is being recorded. Twenty gratings were multiplexed using the exposure schedule calculated with the uniform post-exposure model, and comparison with the result from traditional method confirmed the validity of this model.