Determination of the space-charge field in polymeric photorefractive material

Abstract

We proposed a method for measuring the magnitude of the space-charge field of the polymeric photorefractive materials. In the case of polymeric photorefractive material with low glass transition temperature, optically anisotropic chromophores are known to be reoriented under space-charge field. Simply by adding a pair of crossed polarizer units to a conventional degenerated four wave mixing setup, we could measure the birefringence of the photorefractive materials induced by a newly formed space-charge field. Since the birefringence of a given material is governed by the applied electric field, the space-charge field can be determined from the variation of birefringence using the oriented gas model.