Rotation and Revolution of Optically Trapped Gold Nanorods Induced by the Spin and Orbital Angular Momentum of a Laguerre–Gaussian Vortex Beam

Abstract Optical trapping, spinning, and orbiting of nanoparticles allow the study of nanoscale mechanical, thermal, and optical effects. A circularly polarized Laguerre–Gaussian beam can simultaneously rotate a gold nanorod about its symmetry axis while revolving it around the beam's symmetry axis. The first motion is rotational in character, whereas the second is translational. Effective temperatures of each motion are experimentally obtained and compared with predictions from the Hot Brownian Motion theory. The results also show the optical‐to‐mechanical torque‐transduction efficiency to be equal for the spin and orbital angular momentum.