1C07 Observation of orientational fluctuations due to electrohydrodynamic convection in the vicinity of threshold voltage

Abstract

Nematic liquid crystals with negative dielectric anisotropy and sufficient ionic conductivity exhibit an electrohydrodynamic convection when ac voltages larger than a threshold voltage are applied. The critical fluctuations inducing the convection has been observed below the threshold by means of shadowgraph technique. Here, we present a new alternative method to visualize the fluctuations through a polarizing microscope by using a chiral dopant, and show that the amplitude and relaxation time increase near the transition point.