Optical dispersion of the refractive index modulation in low T-g photorefractive polymers

We measure at different wavelengths the linear and nonlinear optical properties of a new chromophore for photorefractive applications by means of frequency-dependent ellipsometry experiments. We show that the optical dispersion of the refractive index modulation responsible for the high diffraction efficiency in low T-g polymers can be described by a two-level model. (C) 1997 American Institute of Physics.