Spectral hole burning in absorption profiles of metal nanoparticles prepared by laser assisted growth.

We have combined two novel methods, i.e. persistent spectral hole burning and laser assisted growth, to measure the decay time T₂ of surface plasmon excitation in metal nanoparticles of different size at constant well defined shape. The measured values of T₂ amount to 6±0.4fs and are independent of size for diameters ranging from 8 to 25nm. [ABSTRACT FROM AUTHOR]