Global Spectral Analysis of Polaritonic Coupling of Multiple Organic Dyes to a Tunable Fabry‐Pérot Resonator Operating with Mirror Separations up to 10 μm

We study strong optical coupling and the formation of hybrid polaritons by a donor-acceptor pair of J-aggregated dyes separated by up to 11 μm in a tunable Fabry-Pérot resonator. Fitting a phenomenological Hamiltonian to the white light transmission spectra of different cavity-J-aggregate-configurations, for which several hundred spectra were recorded sequentially as function of cavity length, allows us to determine coupling energies as a function of the effective cavity distances. The theoretical analysis shows that certain hybrid polaritons contain contributions from both dyes, making this system a promising platform for polariton-mediated energy transfer at very large distances.