Multicolor Microscopy and Spectroscopy Reveals the Physics of the One-Photon Luminescence in Gold Nanorods

Abstract

This work demonstrates for the first time that one-photon luminescence in gold nanorods is an entirely plasmon-induced process. To achieve this goal, we used confocal microscopy in combination with higher order laser modes as well as light spectroscopy. We show that gold nanorod luminescence can be produced in three different ways: first, by directly exciting their longitudinal and transversal plasmon modes; second, by an energy transfer from the transversal to the longitudinal plasmon mode promoted by electron–holes pairs; and third, by conversion of directly excited electron holes pairs into the longitudinal plasmon mode.