Luminescence enhancement and energy propagation in plasmonic networks

We describe the optical properties of a simple plasmonic network, which consists of silver nanowires coupled with nanocrystals doped with rare-earth-ions. The nanocrystals exhibit anti-Stokes emission called up-conversion. First of all, we demonstrate efficient coupling between a single silver nanowire and nearby nanocrystals via plasmonic excitations. These plasmonic interactions result in an enhancement of the up-converted emission intensity of nanocrystals located in the close vicinity of the nanowires, mostly due to increased radiative emission rates. We prove that luminescence can be either emitted directly by the nanocrystals or transferred to the nanowire. Imaging of angular-resolved emission patterns in the Fourier plane reveals plasmon-mediated luminescence, where the up-converted radiation is emitted via the nanowire antenna as leakage radiation. The luminescence signal can be distributed by plasmonic network for quite long distances reaching tens of micrometers.