A simple frequency‐dependent ellipsometric technique for measuring the birefringence, the Pockels and Kerr properties of low glass‐transition temperature photorefractive polymers is proposed. The technique is applied to the characterization of highly efficient DMNPAA:PVK:ECZ:TNF photorefractive polymers and the determination of the microscopic properties of the DMNPAA molecule. ©1996 American Institute of Physics.