4x4 Matrix Method for Biaxial Media and Its Application to Liquid Crystal Displays

The 4x4 matrix method for uniaxial media developed by Berreman [J. Opt. Soc. Am. 62, 502, (1972)] and by Wohler et. al. [J. Opt. Soc. Am. A5, 1554 (1988)] is extended to biaxial media by making simple modifications to solutions of surface normal wave vector. For uniaxial media, the well known analytical expressions can be directly deduced from the modified solutions. This 4x4 matrix method for biaxial media is applied to demonstrate that, for viewing directions away from the principal planes of an optically compensated bend mode liquid crystal display, the compensation effects of a single biaxial film are generally different fromt those of the combination of two uniaxial films.