Enhanced light extraction from emitters close to clusters of resonant plasmonic nanoantennas

We perform time-resolved fluorescence spectroscopy on clusters of plasmonic nanoantennas covered with a dye–polymer mixture. Dimer antenna structures were fabricated consisting of two interacting gold nanorods with varying lengths and interparticle separation. By combining four individual antennas into a cluster within a diffraction limited spot size, we can couple out half of the dye molecule fluorescence via antenna plasmons. Two-dimensional confocal fluorescence lifetime scans visualize the spontaneous emission enhancement of the molecular fluorescence around the antenna clusters