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Free keywords:
CDTE NANOCRYSTALS; OPTICAL GAIN; EMISSION; SINGLE; MICROCAVITY;
COMPOSITE; DROPLETS; PARTICLE; SPECTRA; CAVITYChemistry; Science & Technology - Other Topics; Materials Science;
Physics;
Abstract:
We report single-mode and multimode lasing from isolated spherical liquid microcavities containing CdSe/ZnS nanocrystal quantum dots. Lasing is observed at densities more than 2 orders of magnitude lower than previously demonstrated or theoretically predicted, assuming a uniform nanocrystal quantum dot distribution. Charged droplets, between 10 and 40 mu m in size, are electrodynamically levitated and optically pumped. Substantial laser signals at low thresholds are measured from the directional emission normal to the pump beam, owing to the high Q cavity modes.