Director Structures in a Chiral Nematic Slab: Threshold Field and Pitch Variations

Abstract The liquid crystal director distribution is determined for a confined chiral nematic slab. The molecular director distribution of the field-controlled chiral nematic slab is directly calculated. The director profiles for the tilt and the twist angles, under different applied fields, are calculated in the slab with weak boundary conditions. Then, the dependence of the threshold field on a dimensionless parameter containing the anchoring and thickness variations is obtained. The variation of the threshold field is found as a function of anchoring strengths for different ratios of the slab-thickness to the pitch, d/P. It confirms that for a constant ratio of d/P, the field decreasing rate in strong anchoring conditions is high and that by decreasing the strength of anchoring, the threshold field becomes approximately constant. This study is based on a stable and simple numerical method that gives accurate results in a short time, compared to the existing methods. The excellent agreement of the solutions with the previously reported solutions shows the usefulness of the method.