Three-dimensional photoluminescence mapping and emission anisotropy of single gold nanorods

Abstract

We use raster-scanning confocal microscopy in combination with radially and azimuthally polarized laser excitation for mapping the three-dimensional (3D) orientation of individual spatially isolated gold nanorods (GNRs). The simultaneous acquisition of both the elastic scattering patterns and the one-photon luminescence patterns of the same GNR allows for determining both the particle position and the orientation with high precision. By analyzing experimental patterns and comparing them to theoretical results obtained by computer simulations, we establish a complete 3D photoluminescence map of single GNRs. Both elastic scattering and luminescence patterns of the same particle are found to display modifications of the refractive index of the dielectric environment. The polarization dependence of GNRs photoluminescence suggests a plasmon-mediated process. © 2012 American Institute of Physics.