Discerning the Origins of the Amplitude Fluctuations in Dynamic Raman Nanospectroscopy
journal contributionposted on 20.02.2016 by Jérémie Margueritat, Alexandre Bouhelier, Laurent Markey, Gérard Colas des Francs, Alain Dereux, Stéphanie Lau-Truong, Johan Grand, Georges Lévi, Nordin Félidj, Jean Aubard, Eric Finot
Any type of content formally published in an academic journal, usually following a peer-review process.
We introduce a novel experimental and analytical method for discerning rare surface-enhanced Raman scattering (SERS) events observable at the nanoscale. We show that the kinetics of the Raman activity recorded on an isolated nanostructure is punctuated by intense and rare events of large amplitude and spectral variations. The fluctuations of thousands of SERS spectra were analyzed statistically in terms of power density functions, and the occurrence of the rare events was quantified by a wavenumber statistics. Our analysis enables one to extract valuable and unique spectroscopic signature of Raman variations usually hidden in time-average or space-average measurements. We illustrate our approach using molecular surface dynamics of gold adatoms on nanoparticles.