Phonon-driven resonantly enhanced polariton luminescence in organic microcavities

Characteristic low-threshold polariton lasing of organic and inorganic microcavity systems can only be achieved with efficient population of the lower polariton ground state. In this regard, the key role undertaken by vibronic replicas and molecular phonon it has been shown experimentally and theoretically predicted by various works. We report here, direct observation of critical enhancement of polariton population density in strongly coupled J-aggregate based organic microcavities. The process highlighted in our study is manifested by discrete maxima of the angular-resolved photoluminescence intensity and interpreted by the mediation of molecular vibrations quanta characteristic of the active material. By measuring the reduced time scale of vibrations driven relaxation dynamics, manifested by sub 100fs buildup times, we emphasized the efficiency of the mechanism to overcome losses channel in disordered J-aggregate systems. Hence, the realization of amplified polariton population with improved relaxation rates paves the way for the observation of low threshold lasing, primary step for developing room temperature organic laser sources and ultra-fast optoelectronic devices with less fabrication complexity than their crystalline counterparts.