The description of the energy density associated with an electromagnetic field propagating through matter must treat two different phenomena: dispersion, the variation of the refractive index with frequency, and dissipation, the loss of field energy by absorption. In many cases, as in common metals, however, both dispersion and dissipation must be taken into account; and their respective contribution vary significantly with the frequency of the electromagnetic field. Plasmonic structures always involve surfaces between dielectrics and metals, and the energy density in the vicinity of the interface figures importantly in the dynamic response of these structures to light excitation in the visible and near-infrared region. Here we consider, from several different viewpoints, light energy propagated and dissipated at surfaces supporting eletromagnetic surface wave, including the important SPP, the surface plasmon-polariton wave guided by the metal-dielectric interface.
Citation: Physical Review B
Pub Type: Journals
plasmon, surface wave, nanostructure