Polariton lasing in a ZnO microwire above 450 K

Exciton-polariton lasing in a one-dimensional ZnO microcavity is demonstrated at high temperature of 455 K. The massive occupation of the polariton ground state above a distinct pump power threshold is clearly demonstrated by using the angular resolved spectroscopy under non-resonant excitation. The temperature dependence of the polariton lasing threshold is well interpreted by two competing mechanisms, i.e., the thermodynamic and kinetic mechanisms. Michelson interference measurements are performed to investigate the temporal and spatial coherence of polariton laser, with the coherence time and coherence length being τc∼0.97 ps and rc∼0.72μm at 440 K and 400 K, respectively.