Parallel collective resonances in arrays of gold nanorods

In this work we discuss the excitation of parallel collective resonances in arrays of gold nanoparticles. Parallel collective resonances result from the coupling of the nanoparticles localized surface plasmons with diffraction orders traveling in the direction parallel to the polarization vector. While they provide field enhancement and delocalization as the standard collective resonances, our results suggest that parallel resonances could exhibit greater tolerance to index asymmetry in the environment surrounding the arrays. The near- and far-field properties of these resonances are analyzed, both experimentally and numerically. © 2014 American Chemical Society.Funding from Spanish MINECO through grants “FUNCOAT” CONSOLIDER CSD2008-00023, “MAPS” MAT2011-29194-C02-01, and from Comunidad de Madrid through grants “NANOBIOMAGNET” S2009/MAT-1726 and “MICROSERES-CM” S2009/TIC-1476. A. V. acknowledges support from Spanish MINECO through FPI grant.Peer Reviewe