Control of single emitter radiation by polarization- and position-dependent activation of dark antenna modes

We study the modification of the decay rates of a single dipolar emitter positioned in the vicinity of metallic linear nanoantennas when higher-order plasmonic excitations are induced. We show that it is possible to effectively tune the enhancement or suppression of both the radiative and nonradiative decay processes by controlling the position and orientation of the dipole with respect to the antenna. Transverse polarization of a single emitter, with respect to the antenna axis, located at the center of the antenna activates dark antennamodes that modify dramatically both the intensity and the spectral features of the decay rates. © 2012 Optical Society of America OCIS codes: 350.5610, 350.4238, 250.5403. Small metallic particles, utilized in various branches of nano-optics [1,2] as optical antennas, are capable of lo-calizing the energy of incident radiation into volumes of sizes far below the wavelength of incoming waves [1]. By reciprocity, antennas also serve as radiation broad-casting systems that tune and shape the emission from a localized energy source such as a single dipolar emitter. Numerous designs of metallic structures have alread