Multipolar effects on the dipolar polarizability of magneto-electric antennas.

We show the important role played by the multipolar coupling between the illuminating field and magneto-electric scatterers even in the small particle limit (λ/10). A general multipolar method is presented which, for the case of planar non centrosymmetric particles, generates a simple expression for the polarizability tensor that directly links the dipolar moment to the incident field. The relevancy of this approach is demonstrated by comparing thoroughly the dipolar moments predicted by the method with full numerical calculations.

Spectral imaging of individual split-ring resonators.

We report on spectral imaging within individual silver split-ring resonators (SRRs) operating in the near infrared-visible range. We classified the optical eigenmodes from the measurement of their energies and nanometer scale spatial distributions. They are plasmonic standing waves that show great similarities with that of nanoantennas.