+-photorefractive CdSe and gold nanowire-doped liquid crystals and polymer-dispersed-liquid-crystal photonic crystals

We have observed enhanced photorefractive responses in CdSe doped nematic liquid crystal cells. The effective intensity dependent refractive index coefficients are on the order of 10(-2) cm(2)/Watt. Using polymer-dispersed mixture of these NLC, 3-D photonic crystals are fabricated by short-exposure direct holographic optical illumination. The resultant structure exhibits 3-D photonic crystal Bragg diffraction and multi-color reflections that can be electronically switched at millisecond speed. Enhanced diffraction efficiency is obtained by doping the liquid crystal with gold nanowires.