Diffraction Analysis of LC Gratings based on Linearly Graded Phase Model for Surface Anchoring Energies

We reported the diffraction analysis of the liquid crystal (LC) binary gratings and the surface anchoring energies for planar and homeotropic alignments. The planar and homeotropic anchoring energies were directly derived based on the linearly distorted director distribution near domain boundaries, in which the distorted lengths correspond to the extrapolation lengths into both planar and homeotropic regions. From the diffraction analysis for the LC binary gratings with various grating periods based on the linearly graded phase model, both distorted lengths into planar and homeotropic regions were simultaneously obtained. In this work, the planar and homeotropic anchoring energies were found to be about $1.4\;{\times}\;10^{-4}\;J/m^2$ and $0.9\;{\times}\;10^{-5}\;J/m^2$, respectively.