E-raamat: Physics of Photorefraction in Polymers

Empirical studies of photorefraction in polymers have often been based on assumptions of comparability between polymers and photorefractive crystals. In contrast to studies of photorefractive crystals, the authors (both of the U. of Manchester, UK) note, there is little evidence that multilevel photorefractive charge trap models are needed. Accordingly, they apply a simple, single-trap level model of photorefraction to polymers which they argue is sufficient to explain the known behaviors of polymers if the reorientation process is allowed to be dispersive, rather than insisting on a characteristic time scale, as happens in models based in comparability. They provide chapters on the charge photogeneration process, the dispersion in charge transportation, and the electro-optical response that creates a phase hologram from the pattern in the electric field. A final chapter considers a simple model of the dispersion in the reorientational electro-optic dynamics of polymers, in which the number of free parameters to be determined from experiment has been reduced in order to obviate the need for many empirical studies. Annotation ©2004 Book News, Inc., Portland, OR (booknews.com)