Optical unwinding and reentrance phenomena in chiral smectic-C liquid crystals

Abstract

We optically measure the molecular reorientation induced by an argon laser in homeotropically aligned chiral smectic-C films. Optical unwinding of the helix is observed and the critical unwinding intensity is determined. We have also developed a theory which not only explains the observed effect but also predicts a novel reentrance phenomenon of the unwinding state. (C) 1998 American Institute of Physics.