Electronic/Nonlinear Optical Effects in Liquid Crystals: Optical Switching in Nematic Twist Cells
Kenneth Singer, Jessica Merlin, Mark Winkler, Platon Korneychuk and Yuri Reznikov
We describe surface mediated charge effects leading to all-optical nonlinear optical responses in nematic liquid crystals.In particular,we have investigated the behavior of a nematic liquid crystal twist cell under dc bias and laser illumination.We have found that the electric field induced Friedericksz transition voltage depends on the intensity of illumination due to these surface-mediated charge effects.This intensity dependent Friedericksz transition can be exploited for all-optical switching. We have demonstrated this effect and suggest a mechanism involving optical control of the surface charge double layer.