Nematic liquid crystals in frequency and amplitude modulated electric fields

In this paper we study peculiarities of behaviour of a nematic liquid cryst al (NLC) in an electric field consisting of two harmonics with different am plitudes and frequencies. The most interesting result is the experimental o bservation of high frequency, stabilization of a low frequency electrohydro dynamic instability in the NLC. A method of measurement of the one frequenc y instability threshold has been proposed. The beating regime of the two fr equency electric held was also studied. The theory developed provides an ex planation for all the experimental results.