Fig. 2: Single-mode lasing characteristics of CQDAMs at high temperature.
From: Ultrastable low-cost colloidal quantum dot microlasers of operative temperature up to 450 K
a Power-dependent emission spectra of a typical CQDAM at 450 K. Inset: three-dimensional optical WGM distribution based on a microsphere with radius R = 590 nm by theoretical simulation. b The excitation density VS the PL intensities at the cavity resonance energy (Ec: 1868 meV) and the nonresonant energy (En: 1863 meV). Plots of emission FWHM of PL spectra VS excitation density. Inset: Lorentzian fitting of the lasing peak with an FWHM of ∼0.6 meV, corresponding to a Q factor of ∼3500. c Typical PL decay profiles of the emission measured under different excitation densities of 0.8 Pth, and 1.5 Pth. The solid lines are the fitting results based on biexponential decay functions. The spontaneous and stimulated radiation lifetimes are 300 and 13 ps, respectively. d The resonant optical modes of CQDAMs with different sizes. Multimode lasing can be obtained and the spacing between two adjacent modes decreases with the increase of cavity size
