Dispersion Relation of Optical Eigen Modes in Chiral Smectic C by 4×4 Matrix Method

Dispersion relations of optical eigen modes (OEM's) in Sm C* are calculated by the 4×4 matrix method. The first order reflection region (full pitch band) consists of only a total reflection region. The structure of the second order reflection region, corresponding to that of the first order in cholesterics, strongly depends on the tilt angle of Sm C* and the propagation direction of OEM's. For a tilt angle smaller or larger than that of light propagation, the reflection region splits into three or consists of a single region with a structure.