Gold nanorod plasmonic upconversion microlaser

Gold nanorods (GNRs) have drawn wide interests among researchers due to their up-conversion emission properties, and have been widely applied as an imaging contrast agent both in vivo and in vitro. The majority of past research and studies focused on luminescence of GNRs excited by a laser at the wavelength blue-shifted from Longitudinal Plasmon Resonance. Here by coating GNRs on an optical resonator, we demonstrated a visible laser at 575nm from GNRs with an approximately 1nm linewidth, pumped by optical resonators with resonance matching Longitudinal Plasmon Resonance of GNRs. The threshold powers have been optimized by varying concentrations of GNRs on toroidal surface, and have been as low as 20μW.