Spectral behavior of localized plasmon resonances in the near- and   far-field regimes. Comment on The spectral shift between near- and far-field   resonances of optical nano-antennas
  In a recent paper by Menzel et al. (Opt. Exp. 22, 9971 (2014)), its authors analyze the spectral red-shift effect of plasmonic resonances of metallic nano-antennas between the far-field and near-field regimes. Here, we demonstrate that their interpretation of this effect is done under the same perspective as one recently reported in Langmuir 29, 6715 (2013); however, the former is incomplete and needs some remarks and clarifications which require additional relevant concepts and arguments of physical significance. 
Fernando Moreno, Pablo Albella and Manuel Nieto-Vesperinas
physics.optics