Polariton states in disordered organic microcavities

In typical organic based microcavities, large values of Rabi splitting are accompanied by any amount of structural disorder. We present a microscopic approach which treats on equal footing the strong light-matter coupling and the disorder scattering which breaks translational symmetry. Through direct numerical diagonalization in a long, but finite, disordered one-dimensional microcavity, the nature of the eigenstates is elucidated and compared to that of the plane-wave-like cavity polaritons of a perfect system. It is shown that delocalized states with well defined wave vectors or strongly localized states may occur, depending on their energy. In particular, at energies close to the excitonic resonance as well as at the bottom of the polariton branches, the states are definitely not plane-wave-like.