To provide novel photopolymers based on specific urethane acrylates as writing monomers, which are suitable for producing a holographic medium, in particular for visual display of images, and to provide a composition containing the photopolymers.

A polyurethane composition comprises a writing monomer component, which contains at least 10 wt.%, based on the total weight of the polyurethane composition, of one or more unsaturated urethanes, as writing monomers and polymeric compounds or corresponding matrix precursors as a matrix for the writing monomers. In the unsaturated urethanes, the p-position of each phenyl group of triphenyl phosphate, triphenyl thiophosphate, and triphenyl methane has a radiation curable group via a urethane bond.