Optical wave propagation in a cholesteric liquid crystal using the finite element method

Abstract

Bragg reflections of cholesteric liquid crystals at normal and oblique incidences were investigated using the finite element method (FEM). Detailed FEM derivations together with the consideration of boundary conditions are given. Two methods for achieving broadband Bragg reflection are analysed: one is to use high birefringence liquid crystal in the uniform pitch structure, the other is to use the gradient pitch structure. In each case, the number of cholesteric pitches required for establishing the Bragg reflection was simulated.