Enhanced localized fluorescence in plasmonic nanoantennae

Reuben Bakker, Purdue University - Main Campus
Hsiao-Kuan Yuan, Purdue University - Main Campus
Zhengtong Liu, Purdue University
V. P. Drachev, Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University
Alexander V. Kildishev, Birck Nanotechnology Center, Purdue University
V. M. Shalaev, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University
Rasmus H. Pedersen, Tech Univ Denmark
Samuel Gresillon, Univ Paris 06, CNRS, LPEM, UPRA5
Alexandra Boltasseva, Birck Nanotechnology Center, Purdue University

Abstract

Pairs of gold elliptical nanoparticles form antennae, resonant in the visible. A dye, embedded in a dielectric host, coats the antennae; its emission excites plasmon resonances in the antennae and is enhanced. Far-field excitation of the dye-nanoantenna system shows a wavelength-dependent increase in fluorescence that reaches 100 times enhancement. Near-field excitation shows enhanced fluorescence from a single nanoantenna localized in a subwavelength area of similar to 0.15 mu m(2). The polarization of enhanced emission is along the main antenna axis. These observed experimental results are important for increasing light extraction from emitters localized around antennae and for potential development of a subwavelength sized laser.