Quasi-steady state exciton-polariton condensation in organic microcavities

Abstract

Strongly coupled organic microcavities are up-and-coming material systems for ambient polaritonics. A broad range of suitable materials made possible the experimental observation of polariton lasing across the whole visible range, as well as device-concepts ranging from ultra-fast transistors and all-optical logic gates to single-photon switching, all at room temperature under ambient conditions. Unlike the case of inorganic semiconductor microcavities, where continuous-wave excitation allows for the replenishment of particle losses, leading to the realization of steady-state polariton condensates, in organic semiconductors photobleaching and polaron formation prevent CW operation. BODIPY dyes have been the subject of thorough studies for their applications in the strong coupling regime. Strongly coupled BODIPY microcavities and polariton lasing in these structures allow for highly monochromatic tunable coherent emission of duration up to ~two picoseconds. Here, we use a single-mode lambda/2 strongly coupled microcavity of a BODIPY dye molecule, employ a single-shot dispersion imaging technique to study polariton lasing in a planar organic microcavity, and achieve a quasi-steady state exciton-polariton condensation under single-shot excitation in such systems. Temporal dynamics of a single-shot exciton-polariton lasing is of particular interest and importance for understanding rates of depletion and replenishment of the exciton reservoir and polariton states, respectively, under pulsed excitation. Moreover, the direct measurement of the condensate lifetime provides valuable insight into the transient processes of nonequilibrium polariton condensation. Long-lasting condensates exceeding polariton lifetime for several orders of magnitude push the system one step closer towards the regime of dynamic equilibrium and could be a missing puzzle towards polariton applications such as connected polariton devices and condensate lattices implemented at ambient conditions, opening the possibility for all-optical polariton circuitry on a chip.