Spatial Pattern Formation in a Cholesteric Liquid Crystal Under a Rapid Temperature Change

We have investigated the characteristic behavior of a cholesteric liquid crystal, cholesteryl oleyl carbonate, under a thermally nonequilibrium condition. It has been found that a rapid temperature increase causes the instability of the uniform planar texture, and a network-like spatial pattern is induced. We have studied this phenomenon by performing two experiments: the spectroscopic measurement of optical transmission and the dynamic light scattering measurement which proves the structural variation of the helical structure and the dynamical fluctuation of the director under the thermally equilibrium condition, respectively. We discuss the mechanism of the spatial pattern formation process by combining the results of these measurements.