Ultrafast Dynamics of Polariton Cooling and Renormalization in an Organic Single-Crystal Microcavity under Nonresonant Pumping

Abstract

Microcavity systems with organic luminescent materials have a hot prospect for room-temperature cavity-polariton devices. The polariton dispersion relation of organic microcavities is significantly different from that of inorganic microcavities due to the strong localization of Frenkel excitons. Also photoexcited particles will undergo a different cooling mechanism until they reach the polariton ground state. In the characterization of efficient polariton condensates, therefore, the polariton cooling dynamics as well as the kinetics of the polariton eigenstate should be measured. Here we present experimental studies on ultrafast dynamics of cavity polaritons in an organic single-crystal microcavity under nonresonant pumping. In time-resolved photoluminescence measurements we observed, for the first time, an ultrafast dynamics of stimulated cooling of the organic cavity polariton. Transient transmission measurement enabled us to investigate the detailed renormalization dynamics of the polariton eigenstate....