Eigen and Coupled Modes on Nanoparticle Aggregate Arrays

M. Csete[1], A. Szalai[1], E. Csapó[2], A. Somogyi[1], I. Dékány[2]
[1]Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
[2]MTA-SZTE Supramolecular and Nanostructured Materials Research Group, University of Szeged, Szeged, Hungary
Published in 2014

Novel class of artificial optical antennas are of great interest in biosensing applications of nanoplasmonics due to their unique and tunable spectral properties. Silver colloid spheres covered with L-cysteine were studied experimentally by spectroscopy and TEM and numerically by a COMSOL Multiphysics® simulation. Experimental studies revealed that the Ag NP-Cys core-shell conjugates prefer to compose versatile aggregates. To inspect the nanophotonical origin of UV and red-shifted maxima one and two dimensional chain geometries were selected. During modeling the eigenmodes with the RF Module the symmetry features of our models were ensured by using artificial mesh with appropriate symmetry. It was demonstrated that by illuminating periodic aggregate arrays of Ag NPs in close proximity of their eigenfrequencies one can achieve large EM-field confinement.