Room temperature lasing of a 3 μm-diameter microdisk.
(a) Emission spectra under pulsed excitation taken at different pump powers (spectra are shifted for clarity). The spectral resolution is 0.17 meV. (b) PL spectrum of the same microdisk under continuous wave excitation, compared to the one of the un-processed active layer (excitation power density: 500 W.cm−2, same spectral resolution). The values of quality factors for some WGMs are indicated. (c) Integrated intensity (filled circles) and linewidth (empty squares) measured for lasing peak A1. The linewidth uncertainty is due to the slight irreversible energy shifts observed along the acquisitions at low excitation power and carrier-induced or temperature-induced effects at high excitation power. The β-factor of the A1 mode is fitted by the rate equation model described in Supplementary Note 2 (plain blue line).