SIGN REVERSAL OF THE LINEAR ELECTROOPTIC EFFECT IN THE CHIRAL NEMATICPHASE

The chiral nematic phase aligned with its helical axis along one prefe rred direction, being parallel to the confining substrates, exhibits a linear electro-optic effect when an electric field is applied normall y to the substrates. The-effect is considered to be of flexoelectric o rigin. A sign reversal of the effects is found when the helix of the c hiral nematic phase changes its handedness, thus revealing the relatio nship between the sign of the linear electro-optic effect and the heli x handedness. Here, we presnt and discuss a simple model of this relat ionship.