Berreman-matrix formulation of light propagation in stratified anisotropic chiral media

We critically analyze the problem of light propagation in stratified birefringent gyrotropic media by introducing a matrix formulation. As a test model we consider the case of short-pitch chiral smectic-C liquid crystals, for which simple descriptions in terms of an effective gyrotropic homogeneous model and of a microscopic periodic structure are available. By comparing reflectances and transmittances from finite and semi-infinite slabs, we show that the homogeneous description is unable to account for some of the properties of the underlying periodic structure, whatever small is the pitch with respect to the light wavelength. Received 11 May 1998