Reorientation of chromophores in dispersive photorefractive polymers

The reorientational dynamics of chromophores in a photorefractive polymer c omposite are characterized by use of a new, analytical, nonexponential expr ession. A single material parameter, the diffusion constant, is used to des cribe reorientation in the material. The effect of plasticization on the di ffusion constant is studied. The relationship between space-charge field gr owth and the biexponential fit to holographic growth is investigated. For t ypical parameters the exponential space-charge field's rise time may be as much as 10 times less than the holographic growth time constant obtained co nventionally. (C) 2001 Optical Society of America.