Planar Texture Improvement in Cholesteric Liquid Crystal Cells

We investigate the effect of thermal annealing (TA) on cholesteric cells. When a cell is heated to the cholesteric–isotropic transition temperature ( T ci ), the cholesteric phase coexists with the isotropic phase. The isotropic domains become oily streaks, but the cholesteric domains merge with each other as the cell naturally cools to room temperature. A repeated T ci TA processes that entails heating the cell to T ci followed by cooling to room temperature effectively suppresses oily streaks and expands planar texture domains. Through this method, a defect-free cholesteric cell is achieved after five repeated T ci TA processes.