Influence Of Molecular Weight On The Photorefractivity Of Polymer/Liquid Crystal Composites

We report on photorefractive composites composed of poly(N-vinyl carbazole) (PVK)/liquid crystal/C-60 with PVK of different molecular weight (MW). The influence of MW on the photorefractivity was studied. The results show that a higher MW leads to a larger two-beam coupling coefficient Gamma and a larger effective electric-optical coefficient. Gamma over 200 cm(-1) is observed for the composite based on the highest MW PVK. (C) 2002 American Institute of Physics.