Abstract

Colloidal nanocrystals are very bright stable fluorophores obtained by chemical synthesis. By use of a confocal microscope, they can be studied at the single-emitter level. This reveals some properties which were hidden in ensemble measurements such as homogeneous emission linewidth However, as nanocrystal emission exhibits strong fast spectral diffusion, the emission measured on a nanocrystal is still broadened by time averaging over the duration of one measurement (typically 100 ms) and the measured linewidths are typically a few meV. In ref. [1] and [2], we proposed a method called photon-correlation Fourier spectroscopy (PCFS) allowing linewidths measurements with very small spectral-diffusion broadening. In ref. [3], we reported a proof-of-principle experiment where linewidths of only 6 μeV were obtained.

© 2009 IEEE