Localized Dynamic Light Scattering: Probing Single Particle Dynamics at the Nanoscale

We developed an experimental technique which probes the dynamics of a single colloidal particleover many decades in time, with spatial resolution of a few nanometers. By scattering a focused laserbeam from a particle observed in an optical microscope, we measure its fluctuations via the temporalautocorrelation function of the scattered intensity