Ultra-fast polariton dynamics in an organic microcavity

We study an organic semiconductor microcavity operating in the strong-coupling regime using femtosecond pump-probe spectroscopy. By probing the photo-induced absorption bands, we characterize the time-dependent population densities of states in the two polariton branches. We found evidence of a scattering process from the upper-branch cavity polaritons to the exciton reservoir having a rate of (150 fs)-1. A slower process similarly populates lower-branch polaritons with a rate of around (3ps)-1