Pregledni rad
Perturbations of Dipole Decay Dynamics Induced by Plasmonic Nano-antennas – A Study within the Discrete Dipole Approximation
Stefania D'Agostino
; Center for Biomolecular Nanotechnologies @UNILE, Istituto Italiano di Tecnologia (IIT), Arnesano, Italy; Physics Department, University of Pavia, Pavia, Italy
Fabio Della Salla
; Center for Biomolecular Nanotechnologies @UNILE, Istituto Italiano di Tecnologia (IIT), Arnesano, Italy; Istituto Nanoscienze-CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT), Lecce, Italy
Lucio Claudio Andreani
; Physics Department, University of Pavia, Pavia, Italy
Sažetak
We report a discrete dipole approximation approach to analyse the perturbations induced by silver nano-particles on the decay dynamics of a point-like emitter placed in their proximity. Due to the excitation of localized surface plasmons, metallic nano-particles behave like optical antennas and are able to convert localized fields into free- propagating optical radiation, and vice versa. Field localization and enhancement induce strong changes on the decay dynamics of dipoles located in the perturbed electromagnetic environment, and these can be faithfully quantified within the framework of classical electromagnetism in terms of total, radiative and non-radiative decay rates. The method is tested on benchmark cases, i.e., nano- spheres and nano-shells, and it is then applied to analytically-unsolvable shapes such as sharp nano-cones and oxide-covered small nano-antennas. Numerical results reveal 105-order enhancements in the total decay rate of the dipole when located very near to the sharp tip, both with and without a thin Ag2O layer. Moreover, the counter- intuitive behaviour of the cone response in relation to the distance between the metal and the source of the radiation is discussed. Applications span from strong coupling studies to time-resolved fluorescence spectroscopy.
Ključne riječi
discrete dipole approximation; optical antennas; localized plasmons; dipole decay dynamics
Hrčak ID:
142542
URI
Datum izdavanja:
1.1.2015.
Posjeta: 955 *