Optical Vortex Induced Rotation of Silver Nanowires

Optical manipulation Of metal nanowires offers the possibility to Control the position, orientation, and associated motions of individual nanowires, particularly by utilizing their plasmonic properties. Here, we demonstrate that the orbital angular momentum of photons in Laguerre-Gauss (optical vortex) beams can induce rotation of single Silver (Ag) nanowires with lengths of over 10 mu m that are lying on (in molecular proximity to) a dielectric surface. We show that the rotation dynamics are governed by plasmonic interactions of the Ag nanowires with linearly polarized light, which yield a sinusoidal optical torque that causes angular acceleration. These results provide important information to understand the angular dependence of plasmonic nanowire-light interactions and extend the repertoire to realize applications in plasmonic lab-on-a-chip systems.