Electrooptic switching in oriented liquid-crystal films

A study was made of the phase and amplitude modulation characteristics of the light passed through oriented films of nematic liquid crystals with a positive permittivity anisotropy. The polarization method was used to record changes in the phase delay of light under the action of voltage pulses. The dependence of the optical response on the amplitude and duration of these pulses was determined, switching rates of several kilohertz were achieved by partial reorientation of the molecules in the crystals. Pairs of positive and negative pulses made it possible to eliminate the influence of the pulse repetition frequency on the modulation conditions and to increase the switching rate.