Evidence of a Bulk Modulation in the Transition from the Transient Planar to the Planar Director Configuration in Cholesteric Liquid Crystal Displays

In cholesteric liquid crystals with a positive dielectric anisotropy, the relaxation from the electric field aligned director configuration to the stable zero field director configuration proceeds via a metastable transient planar director configuration which has a pitch distinct from the equilibrium state. Here, the transition from the transient planar to the equilibrium zero-field state is shown to occur via a Helfrich-type instability which continuously leads to an in-plane helical structure. The equilibrium planar state is seen to grow continuously from the in-plane state, leaving behind walls whose length then spontaneously shrinks.