Electric field-induced second harmonic generation studies of chromophore orientational dynamics in photorefractive polymers

Photorefractive (PR) polymers are promising for use in various applications that require fast response times. The main factors that determine the PR speed in polymers are photoconductivity and chromophore reorientation in an electric field. In this article, we investigate the chromophore reorientational dynamics in various PR composites using the electric field second harmonic generation (EFISHG) technique, and then relate it to the PR dynamics observed in a four-wave mixing holographic experiment. We also report on the enhancement of the EFISHG signal in the presence of HeNe light, which we attribute to a photoinduced internal electric field that formed in the PR polymer. (C) 2002 American Institute of Physics.