INVESTIGATIONS ON THE FLEXOELECTRIC AND ELECTROCLINIC EFFECT IN A CHOLESTERIC PHASE WITH TWIST INVERSION

The linear flexoelectrooptic effect in short-pitch cholesterics was in vestigated for four configurations of a compound with two chiral cente rs. One of the four compounds, the (S,S) configuration, is a single co mponent twist inversion cholesteric and we were able to study the elec troclinic effect of the compound in the unwound state around the twist inversion point. This made it possible to separate the electroclinic tom the flexoelectric electro-optic response and our results show that the electroclinic deflection of the optical axis is about 100 times s maller and 100 limes faster than the flexoelectric one Moreover, this is the first investigation of the electroclinic effect, far from the N -SmC* transition, in a single component N* liquid crystal.