Dynamic Image Analysis for the Fluctuations of Electrohydrodynamic Convection in a Homeotropically Aligned Nematic Liquid Crystal

Abstract

We have investigated the pattern fluctuations of electrohydrodynamic convection in a homeotropically aligned nematic layer by means of the dynamic image analysis. The time correlation function C_k(t) for the spatial Fourier coefficient was obtained from the observed patterns and exhibited the relaxational type. In the long-wavelength regime, it was found that the relaxation frequency is expressed as τ^-1(k)=α+κ k², where the coefficients α and κ are functions of a normalized voltage ε, and τ^-1(0)∝ε. These results indicate that the collective fluctuation of pattern induced by rolls should be diffusive. The analogy with the second-order phase transition induced by a relaxational soft mode is also discussed.