Liquid-crystal modulator operating at 10.6 μ

A liquid-crystal modulator operating at 10.6μ was constructed. The modulation effect was based on a cholesteric-nematic phase transition in a mixture of cyanobiphenyls with a cholesteric additive. The control voltage was 90 V. When a control voltage pulse of 4-msec duration was applied to a cell of length 40μ, the turn-on time was less than 1 msec, the turn-off time was less than 5 msec and the contrast ratio was 1:10. The use of bipolar pulses made it possible to reduce the turn-off time to less than 2 msec.