Broadband spontaneous emission rate enhancement through the design of plasmonic nanoantennas

Abstract

We numerically investigate and experimentally demonstrate a new route to controllably manipulate the spontaneous decay rate of dipole emitters in coupled plasmonic modes. The structure under investigation is an hexagonal close-packed array of gold core - silica shell nanoparticles (NPs) sandwiched between two gold films. We show that the interaction of localized and propagating surface plasmon polaritons can dramatically enhance the spontaneous emission rate of quantum emitters (rhodamine isothiocyanate) grafted in the NP silica shell. This strong enhancement (70−100 times) further occurs on the whole, broadband emission spectrum (565 nm to 640 nm) of the emitters