Open AccessSpinning and orbiting motion of particles in vortex beams with circular or radial polarizations
Author(s) -
Manman Li,
Shaohui Yan,
Baoli Yao,
Yansheng Liang,
Peng Zhang
Publication year - 2016
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.24.020604
Subject(s) - physics , angular momentum , optical vortex , topological quantum number , circular motion , optics , circular polarization , spinning , polarization (electrochemistry) , light beam , vortex , torque , optical force , radial polarization , orbital motion , optical tweezers , classical mechanics , laser beams , laser , quantum mechanics , materials science , mechanics , chemistry , laser beam quality , composite material , microstrip
Focusing fields of optical vortex (OV) beams with circular or radial polarizations carry both spin angular momentum (SAM) and orbital angular momentum (OAM), and can realize non-axial spinning and orbiting motion of absorptive particles. Using the T-matrix method, we evaluate the optical forces and torques exerted on micro-sized particles induced by the OV beams. Numerical results demonstrate that the particle is trapped on the circle of intensity maxima, and experiences a transverse spin torque along azimuthal direction, a longitudinal spin torque, and an orbital torque, respectively. The direction of spinning motion is not only related to the sign of topological charge of the OV beam, but also to the polarization state. However, the topological charge controls the direction of orbiting motion individually. Optically induced rotations of particles with varying sizes and absorptivity are investigated in OV beams with different topological charges and polarization states. These results may be exploited in practical optical manipulation, especially for optically induced rotations of micro-particles.