Off-Resonant Optical Excitation of Gold Nanorods: Nanoscale Imprint of Polarization Surface Charge Distribution

We report on the nanoscale optical characterization of gold nanorods irradiated out of their plasmonic resonance. Our approach is based on the reticulation of a photopolymerizable formulation locally triggered enhanced electromagnetic fields. The tiny local field enhancement stems from the surface polarization charge's associated with the electric field discontinuity at the metal/dielectric interface. This allows us to get a nanoscale signature of the spatial distribution of the surface charge density in metallic nanoparticles irradiated off resonance