(American Chemical Society (ACS), 2010) Lassiter, Joseph; Sobhani, Heidar; Fan, Jonathan A.; Kundu, Janardan; Capasso, Federico; Nordlander, Peter; Halas, Naomi J.
Clusters of plasmonic nanoparticles support Fano resonances. Here we show that this spectral feature produced by the interference between bright and dark modes of nanoparticle cluster, is strongly dependent upon both geometry and local dielectric envrionment. This permits a highly sensitive tunability of the Fano dip in both wavelength and amplitude by unprecedented sensitivity to dielectric environment with a local surface plasmon resonance figure of merit of 5.7, the highest yet reported for localized surface sensing in a finite nanostructure.
