Strong Exciton-Photon Coupling In Dye-Doped Polymer Microcavities

Organic strongly coupled microcavities are of crucial importance in broad application fields, ranging from creation of Bose-Einstein condensates to control of chemistry reactions. Generally, strong coupling occurs in microcavities containing large ensembles of molecules, which, however, may suffer from molecular aggregation and luminescence quenching, restricting the optical applications of the microcavities. Here, the emission properties of dye-doped polymer microcavities in strong coupling regime are investigated. The dispersion of dye molecules suppresses the aggregation-caused quenching, and therefore the microcavities exhibit strong photoluminescence (PL) corresponding to the polariton branches. The time-resolved PL measurement results reveal that the observed long PL lifetimes of the microcavities are dominated by the rates of the slow relaxation from the exciton reservoir to the polariton branches. The results will provide a useful enlightenment for using dye-doped polymer microcavities to investigate strong coupling and construct polaritonic devices.