High environmental compatibility photopolymers compared to PVA/AA based materials at zero spatial frequency limit

In holographic applications the direct parameters determination of photopolymers as optical recording media is a very difficult task due to the presence of two different phenomena: polymer formation and monomer diffusion. We propose a direct method based on zero spatial frequency recording, to eliminate the diffusion influence, and on interferometric techniques, both in transmission and in reflection, to obtain quantitative values of: shrinkage, polymerization rate, polymer refractive index and relation between polymerization and recording intensity. Recent investigations confirm the toxic potential of acrylamide. Starting from polyvinylalcohol/acrylamide photopolymer we have proposed different compositions of new competitive photopolymers with high environmental compatibility. We have studied the ways to optimize the optical behavior and the environmental compatibility. Parameters comparison with the polyvinylalcohol/acrylamide photopolymers shows significant differences.