We demonstrate holography in a traditional two-component holographic photopolymer in which the solid polymer host matrix has three distinct sets of material properties: 1) an initially liquid state appropriate for formulation and casting into the desired final shape, 2) a rubbery state with low glass transition temperature appropriate for holographic recording, and 3) a final higher modulus state with improved mechanical robustness. The general chemical scheme is to form the second stage rubbery polymer network via a thiol-acrylate Michael addition with an excess of one functional group. Holographic recording then takes place via radically initiated photopolymerization of a mobile high refractive index monomer, per the common two-chemistry process. During final flood illumination of the material, the remaining monomer and excess functional groups are polymerized to increase crosslink density and improve the mechanical properties of the matrix. We described three such material schemes and report general trends. We demonstrate high (96%) efficiency holographic recording, low (1.1%) shrinkage, no oxygen sensitivity and stage 2 glass transition temperatures at or above room temperature, sufficient to enable self-supporting films.
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