Scattering and near fields of a metallic nanoparticle. (a) Scattering cross section of a 120-nm radius Ag nanoparticle with dielectric function according to a Drude fit; sum and allocation to different order and electromagnetic (E/M) modes. (b) Near field distribution of the electromagnetic field around the nanoparticle for the dipole, the quadrupole, the hexapole, and the octopole electric mode at wavelengths of 688, 426, 340, and 298 nm, respectively, which correspond to the maxima in scattering (incident light from the top).
Schmid et al. Nanoscale Research Letters 2014 9:50 doi:10.1186/1556-276X-9-50