Accurate modelling of multilayer chiral nematic devices through the Berreman 4 x 4 matrix methods

The optical properties of chiral nematic liquid crystal devices have been accurately measured and modelled across the visible spectrum. The devices studied are identical in construction to those that employ the electro-optic properties of chiral nematic materials, including reflective displays, electrically controlled optical filters, light modulators and optical shutters. The Berreman 4 x 4 matrix technique was used in the study and the properties of the conductive, alignment and liquid crystal layers were encompassed in the modelling through direct matrix multiplication. We demonstrate that by including all the optical layers in the theoretical model, excellent agreement can be obtained between theory and experiment for all values of incident polarization, providing a powerful predictive tool. We report values for the optical indices of polyvinyl alcohol, polyimide and indium tin-oxide layers in different devices across the visible spectrum.