Numerical Calculation of Optical Eigenmodes in Cholesteric Liquid Crystals by 4×4 Matrix Method

Abstract

Light propagation in helical structures is formulated as an eigenvalue problem based on Berreman's 4×4 matrix. Diagonalization of the secular equation is carried out to obtain the optical eigenmodes as a function of wavenumber and propagation direction relative to the helical axis, and sets of the optical eigenmodes are found to be classified into four types, whose appearance strongly depends on the wavenumber and the propagation direction. The selective and total reflections in cholesteric liquid crystals are characterized by the types of the eigenmodes for various angles of incidence.