On the mechanism of orientational photorefractivity in polymer dispersed nematics

An unusual dependence of the diffraction efficiency on the applied electric field was observed in four-wave mixing experiments on polymer dispersed ne matics. The data were interpreted on the basis of a simple model which cons iders the orientational nature of the photorefractivity in liquid crystalli ne materials. Such model should also be of relevance for any material with orientational contributions to photorefractivity. (C) 2000 Elsevier Science B.V. All rights reserved.