<title>Photopolymer recording materials for holography: some recent developments</title>

Abstract

The use of highly viscous formulations based on multifunctional acrylates and on various sensitizers allows holograms to be recorded through a photochemically induced polymerization. After a preillumination under homogeneous deep UV exposure, these materials are able to generate a tridimensional network in the cavity of which residual monomers can diffuse easily. When irradiated holographically, these systems become more and more rigid and reach, ultimately, a stage of complete photochemical inertness so that they do not require any chemical or physical post-treatment. Depending on the structure of the sensitizer, the range of sensitivity extends over the visible and near infrared up to 850 nm. At best, no more than 30 mJ/cm^-2 are required to record a permanent hologram at 514 nm.