A microcavity strongly coupled to two molecular crystalline slabs

We study two crystalline organic slabs inside a microcavity in the strong coupling regime. Using a microscopic theory, we derive the cavity-exciton-polariton dispersion relations and quantum states. As resonant materials we consider anisotropic organic crystals with one molecule per unit cell. In anisotropic organic cavities the polaritons are a coherent superposition of the Frenkel excitons and both cavity mode polarizations, which is in contrast to typical inorganic semiconductor cavities in which TE and TM modes are not mixed. The organic slabs, made of different materials, are spatially separated in the cavity and interact with each other only via their coupling with the cavity photons. Four polariton branches are obtained with a strong hybridization between excitons from the two slabs. Reflection, transmission, and absorption spectra are calculated using the quasi-mode formalism.