Strong enhancement of the radiative decay rate of emitters by single plasmonic nanoantennas.
We demonstrate a strong, 5-fold enhancement of the radiative decay rate from highly efficient fluorescent dye molecules around resonant optical nanoantennas. The plasmonic modes of individual gold dimer antennas are tuned by the particle length and the antenna gap, providing control over both the spectral resonance position and the near-field mode profile of the nanoantenna. Resonant enhancement of the radiative and nonradiative decay rates of a fluorescent dye is observed, resulting in an increase of the internal quantum efficiency from 40% up to 53% for single antennas, and up to 59% for antenna clusters. This improvement of the already high quantum efficiency of the dye molecules is in agreement with electrodynamic model calculations that predict a maximum attainable efficiency around 80% due to nonradiative losses in the metal.
FOM Institute for Atomic and Molecular Physics AMOLF, c/o Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven, The Netherlands. muskens@amolf.nl
O L
OL
Muskens
V
V
Giannini
J A
JA
Sanchez-Gil
J
J
Gómez Rivas
D005456:Fluorescent Dyes / Q000737:chemistry*; D006207:Half-Life; D007700:Kinetics; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013050:Spectrometry, Fluorescence / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*
D005456:Fluorescent Dyes