Coupled Chiral Optical Tamm States in Cholesteric Liquid Crystals

The modes formed by two coupled chiral optical Tamm states localized at the interfaces between a photonic cholesteric liquid crystal conjugated with polarization-preserving anisotropic mirrors have been analytically and numerically investigated. These modes are only excited at the diffracting polarization of incident light. As the cholesteric layer thickness decreases, the spectral splitting of the localized state frequency is predicted. The splitting value depends on the crystal layer thickness. At the nondiffracting circular polarization, the localized modes are not excited, and the system becomes similar to the Fabry–Pérot cavity containing an anisotropic helical structure