A New Method for Measuring the Azimuthal Anchoring Energy of a Nematic Liquid Crystal

Abstract
We have proposed a new optical method for measuring the twist angle of twisted nematic cells, and the method has been applied to obtain the azimuthal anchoring energy for a nematic liquid crystal. The method is based on a modulation in the polarization state of an incident probing laser beam to the sample cells, and the resulting transmitted intensity of the beam is theoretically analyzed through the 2×2 Jones matrix method. The obtained anchoring energy for the azimuthal distortion is about 1.5×10-5 J/m2 for a polyvinylalcohol alignment film; which is about two orders of magnitude lower than that for the corresponding polar anchoring energy.