Peter Palffy-Muhoray
Liquid Crystal Institute
Kent State University
Abstract: Polarized light falling on dye doped liquid crystals appears to exert a torque which changes the orientation of the liquid crystal. We show that this reorientation cannot be the result of angular momentum transfer from the light, and propose that `rotation without torque' occurs via an orientational ratchet mechanism, where the dye molecules act as rotors of optically driven Browninan motors. We compare the results of simulations with experiments, and discuss novel aspects of the nonlinear optical response.