Optically induced rotation of Rayleigh particles by vortex beams with different states of polarization

• States of polarization of vortex beams affect the optically induced orbital motion of particles.
• The dependences of the force and orbital torque on the topological charge, the size and the absorptivity of particles were calculated.
• Focused vortex beams with circular, radial or azimuthal polarizations induce a uniform orbital motion on particles.
• Particles experience a non-uniform orbital motion in the focused linearly polarized vortex beam.
• The circularly polarized vortex beam is a superior candidate for rotating particles.

Optical vortex beams carry optical orbital angular momentum (OAM) and can induce an orbital motion of trapped particles in optical trapping. We show that the state of polarization (SOP) of vortex beams will affect the details of this optically induced orbital motion to some extent. Numerical results demonstrate that focusing the vortex beams with circular, radial or azimuthal polarizations can induce a uniform orbital motion on a trapped Rayleigh particle, while in the focal field of the vortex beam with linear polarization the particle experiences a non-uniform orbital motion. Among the formers, the vortex beam with circular polarization induces a maximum optical torque on the particle. Furthermore, by varying the topological charge of the vortex beams, the vortex beam with circular polarization gives rise to an optimum torque superior to those given by the other three vortex beams. These facts suggest that the circularly polarized vortex beam is more suitable for rotating particles.