Local-field anisotropy in cholesteric liquid crystals

The first experimental values of the Lorentz tensor components L _j for the cholesteric and smectic A phases of derivatives of cholesterol have been obtained using the dispersion of the refractive indices in the visible range. The temperature dependence of the components L _j has been determined; it is invariant with respect to the cholesteric-smectic A phase transition. The effect of the isotropization of the Lorentz and local field tensors with decreasing anisotropy of the molecular polarizability has been revealed.