Author: Antonio Cricenti
Requested Type: Poster
Submitted: 2015-03-07 14:10:30
Co-authors: M. D'Acunto, M. Luce
National Research Council
via del Fosso del Cavaliere 10
The scattering cross-section of metallic nanoparticles depends strongly on their size, morphology and index of refraction. In a special way, gold and silver nanoparticles are known to show pronounced plasmonics resonances in the visible range. These plasmonics resonances are understood as the result of collective oscillations of the free electrons upon excitation by the appropaiate optical near-field. Plasmon resonances of individual gold particles as well as silver nanoparticles can be recorded using a Scanning Near-field Optical Microscope (SNOM). We show evaluations and measurements of the plasmon resonances of single gold and silver nanoparticles with diameters ranging from 40-150nm, in different dielectric matrices, ranging from animal cells to ZnO2. The general trend of the spectrum agrees very well with the expectations of the classical Mie theory. In addition, we have considered also the case of clusters of metallic nanoparticles, where the classical Mie theory fails and it must be revised .
 A. Cricenti, M. Luce, D. Moroni, E. Salvetti, M. D'Acunto , Optoelectronics Review 23, 58 (2015)