Electro-optical effects in liquid crystals with dielectric dispersion

The dielectric dispersion in uniaxial nematic liquid crystals creates a "dielectric memory" effect whereby the polarization induced by the electric field decays exponentially with time rather than instantaneously, as in materials without dispersion. The induced polarization couples linearly with the electric field. This linear coupling allows one to accelerate the director relaxation towards the "off" state by a specially designed electric pulse of a proper polarity and duration We show theoretically and experimentally the possibility of electrically driving the director towards the off state, thereby decreasing the switching time.