Customization of a self-processing polymer for obtaining specific diffractive optical elements

Photopolymerizable materials are capable of recording volume holograms via a change in refractivity of the layer. On illumination by an interference pattern around 500 nm, polymerization and diffusion led to regions with various segment densities. A modulation of the refractive index took place, thus giving rise to permanent thick phase gratings created in situ in the emulsion. This modulation was estimated at 7×10−3, corresponding to diffraction efficiencies of ca. 80% for transmission holography. Applications for the fabrication of diffractive optical elements can be expected in view of the experimental results and the simplicity of use. For instance, the duplication of computer-generated holograms on a photopolymerizable film led to thick phase holograms with higher diffraction efficiencies. Substrate-mode polarizing elements were also produced, taking advantage of the laminated property since this emulsion was embedded between two glass plates.