Dendritic optical antennas: scattering properties and fluorescence enhancement

With the development of nanotechnologies, researchers have brought the concept of antenna to the
optical regime for manipulation of nano-scaled light matter interactions. Most optical nanoantennas
optimize optical function, but are not electrically connected. In order to realize functions that require
electrical addressing, optical nanoantennas that are electrically continuous are desirable. In this article,
we study the optical response of a type of electrically connected nanoantennas, which we propose to
call “dendritic” antennas. While they are connected, they follow similar antenna hybridization trends
to unconnected plasmon phased array antennas. The optical resonances supported by this type of
nanoantennas are mapped both experimentally and theoretically to unravel their optical response.
Photoluminescence measurements indicate a potential Purcell enhancement of more than a factor of 58.