Electro-optical and conductive properties of polymer liquid crystal composite film

Polymer-dispersed liquid crystal films, using polymethyl methacrylate and nematic liquid crystal E3 (B&H) were obtained. The electro-optical effects were investigated using He-Ne lasers of different powers and a.c. electric fields of different frequencies applied across the composite film. The measurements of the transmitted light intensity through the composite film were carried out without any polarizers. At low frequencies, the emergent optical signal is modulated in amplitude, doubling the frequency of the a.c. driving field. In the kHz frequency range, the decrease of the fluctuations of the transmitted light with the increase of the frequency was noticed. The conductive properties of the polymer dispersed liquid crystal composite films and the contribution of the nonlinear effects to the electric conduction were determined.