Quasilinear electro-optical response in a polymer-dispersed nematic liquidcrystal

Polymer-dispersed nematic liquid crystals are known to exhibit a quadratic electro-optic response. For practical applications, a linear dependence on the applied electric field is often required. In this letter, polymer-dispe rsed nematic liquid crystal films with a built-in dc electric field are sho wn to be good electro-optical devices with a linear response. The built-in electric field is obtained by energizing films with an external dc field. T he electro-optical response dependence on the strength and frequency of the driving field is discussed. (C) 2000 American Institute of Physics. [S0003 -6951(00)03549-X].