Organic photorefractive materials have only recently been considered as alternatives to inorganic crystals such as lithium niobate, despite the fact that they offer possible advantages, such as mechanical flexibility, low fabrication costs, and the ability to chemically tune the properties of the material. The influence of the nonlinear optical chromophore on various phenomena observed in a photorefractive polymer is reported on the basis of a study of samples derived from poly(N-vinylcarbazole) sensitized with 2,4,7-trinitro-9-fluorenone.