Diffraction Efficiencies of of SeO2 / Acrylamide Modified Photopolymer

The highest diffraction efficiency(DE) value after illuminations and post-curing of photopolymer films were obtained at the SeO₂ /acrylamide(AA) Ratios of AA 3.0g, SeO₂ 1.0 g and the DE´s were stable values of over 90%. By the addition of SeO₂, the maximum DE at the initial stage of illumination reached at 300 seconds, which suggests SeO₂ slow down the photopolymerization of DE variation curve for the optimum composition during extended-time illumination of 9,000 seconds resembles sin curve due to the combination of the monomer diffusion and the photopolymerization, and the photopolymer film expanded at about 8% after photopolymerization due to monomer migration.