Bistable diffractive electro-optical effect in cholesteric gels

The present study shows that a cholesteric gel consisting of a low molar mass liquid crystal and a highly crosslinked anisotropic network can be switched between a transparent and a colored scattering state. The latter state can be induced in an initially non-aligned cholesteric liquid crystal by an electric field, as described recently by Chilaya and coworkers. A short pulse of an electric field can be used to select between the two states which are stable at zero field. The angular dependence of the wavelength of the diffracted light is studied in detail and explained by the known properties of the spatially periodic cholesteric structure.