Bistable Switching in Photorefractive Surface Stabilized Ferroelectric Liquid Crystals

Abstract

By using a photogenerated space-charge field to reorient the spontaneous polarization, we report an approach towards the optical control of switching in a surface stabilized ferroelectric liquid crystal that exhibits two stable orientational states. The space-charge field was generated on the surfaces of the SSFLC device, by sandwiching the FLC between two photoconducting layers, or within its bulk by doping. In the second case, we observed the formation of a grating, stable at least for months, which can be easily erased and rewritten. Experiments have been done to probe its photorefractive nature.

Keywords:

• bistability
• liquid crystals
• photorefractivity
• SmC*

Acknowledgments

This work has been partially supported by MIUR under the projects “Molecular and Organic/Inorganic Hybrid Nanostructure for Photonics – FIRB 2001” and PRIN 2004. We thank Marc Radcliffe for providing us with the liquid crystal L-15278 used in this study.