Fig. 3: Polariton condensation in the PDI-O microribbon.
a–c AR μ-PL spectra of the PDI-O microribbon measured at 0.8Pth, 1.0Pth, and 1.5Pth, respectively. Dashed curves are fitted polariton dispersion. When the pump fluence reaches a threshold, the polariton emission collapses to the bottom of the polariton dispersion with a sharp increase of intensity, suggesting the onset of polariton condensation. The microribbon was pumped by a pulsed laser (400 nm, 150 fs, 1 kHz). d Emission intensity and FWHM at ky = 0 (θ = 0) as a function of pump fluence. The PL intensity was plotted on a log–log scale. Error bars indicate the 95% confidence intervals obtained from the fits to the measured PL spectra. e The time-resolved PL decay profiles at 0.5Pth (red) and 1.5Pth (blue). The lifetimes below and above Pth are 277 and 47 ps, respectively. f The image of the interference pattern in Young’s double-slit interferometry experiment below the threshold. g The image of the same microribbon recorded above the threshold. Scale bars are 8 μm. The x- and y-direction in f and g correspond to the direction of the microribbon width and length, respectively.
