Dielectric enhancement of chiral flexoelectro-optic switching

Abstract

The chiral flexoelectro-optic effect is a candidate for realising sub-millisecond electro-optic technologies. Here, we discuss how flexoelectro-optic switching in cholesteric structures can be enhanced by using the dielectric coupling of the field to materials with negative dielectric anisotropy. An experiment is described that can measure the dielectric effect on flexoelectric switching, and the technique is applied to a chiral nematic mixture E7+3.5%R5011. We explore numerically the optimal liquid crystal parameters to best exploit the effect. An enhancement of up to 1° is demonstrated numerically.

Keywords:

• cholesteric
• flexoelectric
• flexoelectro-optic
• dielectric
• sub-millisecond
• anisotropy

Acknowledgements

B.I.O. wishes to thank Merck Chemicals Ltd, UK, a subsidiary of Merck KGaA, Darmstadt, Germany, for the supply of materials, and the EPSRC and Merck for financial support through a CASE award.