Open AccessPlasmonic particles set into fast orbital motion by an optical vortex beam
Author(s) -
Anni Lehmuskero,
Yanming Liu,
Peter Johansson,
Mikael Käll
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.004349
Subject(s) - physics , optics , plasmon , optical vortex , light beam , beam (structure) , optical tweezers , angular momentum , vortex , photon , laser , classical mechanics , thermodynamics
We optically trap plasmonic gold particles in two dimensions and set them into circular motion around the optical axis using a helically phased vortex laser beam. The orbiting frequency of the particles reaches 86 Hz, which corresponds to a particle velocity of the order 1 mm per second, for an incident laser power of a few tens of milliwatts. The experimentally determined orbiting frequencies are found to be well in line with the notion that the beam carries an orbital angular momentum of ħl per photon.