Room Temperature Polariton Emission from Strongly Coupled Organic Semiconductor Microcavities

We report a room temperature study of the strong exciton-photon coupling regime in a planar microcavity, containing cyanine dye aggregates with delocalized exciton wave functions ( $J$ aggregates). Giant Rabi splittings of 80 meV between upper and lower polariton branches are observed and cavity polariton emission is detected from the lower polariton branch. The small linewidth and large oscillator strength characteristic of $J$ aggregates make them a favorable physical structure to allow the observation of strong coupling for organic semiconductors.