Orientational Hologram Memory in Polymer Dispersed Liquid Crystals Doped with Fullerene

Abstract

A novel type of orientational photorefractive material based on polymer dispersed liquid crystals (PDLCs) doped with fulleren (C₆₀) was presented. The liquid crystals doped with C₆₀ showed photoconductivity and the holographic grating formation mechanism was originated in the space charge field and resulting reorientation of liquid crystal molecules. The Raman-Nath type of gratings in the PDLCs with a dc applied filod were written by the photorefractive-like space charge field and the large refractive index modulation of the order of 10^-3 was obtained. In addition, a stable memory effect of the reorientation was obtained for a 40 wt/60 wt (polymer/liquid crystals) sample.