Photopolymer recording media for high density holographic data storage

To better meet the needs of holographic data storage, we designed a new type of polymer system that is composed of two independently polymerizable and compatible chemical systems: low refractive index matrix precursors and high refractive index photopolymerizable monomers. The matrix of our media is formed by an in-situ polymerization to yield a cross-linked network in the presence of the photopolymerizable monomers, which remain dissolved and unreacted. Holographic exposure polymerizes the photoactive monomer(s); the unreacted monomers diffuse through the matrix producing a modulation in the refractive index that is determined by the difference between the refractive indices of the monomer and matrix.