Nanoantenna array-induced fluorescence enhancement and reduced lifetimes

Reuben M. Bakker, Purdue University - Main Campus
V. P. Drachev, Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University
Zhengtong Liu, Purdue University - Main Campus
Hsiao-Kuan Yuan, Purdue University - Main Campus
Rasmus H. Pedersen, DTU - Technical University of Denmark
Alexandra Boltasseva, Birck Nanotechnology Center, Purdue University
Jiji Chen, Purdue University - Main Campus
Joseph Irudayaraj, Birck Nanotechnology Center, 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

Abstract

Enhanced fluorescence is observed from dye molecules interacting with optical nanoantenna arrays. Elliptical gold dimers form individual nanoantennae with tunable plasmon resonances depending upon the geometry of the two particles and the size of the gap between them. A fluorescent dye, Rhodamine 800, is uniformly embedded in a dielectric host that coats the nanoantennae. The nanoantennae act to enhance the dye absorption. In turn, emission from the dye drives the plasmon resonance of the antennae; the nanoantennae act to enhance the fluorescence signal and change the angular distribution of emission. These effects depend upon the overlap of the plasmon resonance with the excitation wavelength and the fluorescence emission band. A decreased fluorescence lifetime is observed along with highly polarized emission that displays the characteristics of the nanoantenna's dipole mode. Being able to engineer the emission of the dye-nanoantenna system is important for future device applications in both bio-sensing and nanoscale optoelectronic integration.

Discipline(s)

Nanoscience and Nanotechnology