We recently demonstrated a novel polariton laser in an organic system operating at room-temperature.
Optica 4, 31 (2017).
Hybrid light-matter quasi-particles known as exciton-polaritons have inspired decades of interdisciplinary research. Efforts have largely focused on semiconductor microcavities. Therein, interactions between quantum well excitons lead to strong nonlinearities, and photons can be stored for relatively long times in high quality cavities. These features led to the first observations of Bose-Einstein condensation (BEC) and superfluidity in optics. However, a key early vision of the field — the possibility to achieve a coherent light source at low threshold powers without the need for population inversion, i.e. a polariton laser — has remained in the realm of proof-of-principle experiments. In an effort to overcome some of the material-related limitations hampering applications of exciton-polaritons, as well as to explore novel light-matter states associated with distinct types of excitons, several researchers have turned their attention to organic materials. While organic systems are generally disordered, their excitons can have large transition dipole moments allowing them to couple strongly to light at room temperature. Indeed, polariton lasing/BEC and superfluiditiy have recently been observed in organic excitonic systems.
Recently we observed polariton lasing in an array of metallic nanoparticles coated with organic molecules. Interestingly, we reduced the threshold power for polariton lasing in organic systems to a record low-value by increasing the degree of light–matter coupling. These results demonstrate the suitability of organic systems for room temperature studies of quantum fluids of light.
Quantum fluids of light in organic room-temperature systems