Description of optical properties of cholesteric photonic liquid crystals based on Maxwell equations and Kramers-Kronig relations

Abstract

Transmission spectra and rotation of the plane of polarization of light were measured on perfect samples of cholesteric liquid crystal. We found peculiarities of the spectral dependence of rotation of the plane of polarization related to Pendell\"osung oscillations that were predicted theoretically but never observed experimentally. The experimental data are well described by expressions based on an analytical solution of the Maxwell equations. An approach based on fundamental Kramers-Kronig relations is used to describe the optical properties of the photonic crystal. It is shown that the rotatory power of cholesterics consists of two parts: one of them is related to the diffraction-induced circular dichroism whereas the other one originates from the tails of the Mauguin rotation of the plane of light polarization.