Extension of the discrete sources method to investigate the non-local effect influence on non-spherical core-shell particles

Abstract

The Discrete Sources Method (DSM) has been extended to model non-spherical, axisymmetric core-shell particles by taking into account the Non-local Effect (NLE). For this purpose, the Generalized Non-local Optical Response (GNOR) model of the NLE has been employed. By using the extended DSM numerical scheme, prolate and oblate core-shell spheroidal particles have been examined. The simulation results show that the influence of the NLE on both the far and the near field properties of plasmonic core-shell particles is essential. In particular it has been found that the plasmon resonance amplitude is decreased by about 40%, the near field intensity is reduced up to one order of a magnitude, and the blue shift of the plasmon resonance can reach value of 15 nm. Besides, it has been demonstrated that a larger shell refractive index leads to a higher value of the plasmon resonance.