Direction reversal of the optical spin torque on a Rayleigh absorptive sphere in vector Bessel polarized beams. (29th December 2016)

• Record Type: Journal Article
• Authors: Yang, Ruiping; Li, Renxian; Qin, Shitong; Ding, Chunying; Mitri, F G
• Is Part Of: Journal of optics. Volume 19:Number 2(2017:Feb.)
• Publication Date: 2016-12-29
• Subjects: optical spin torque -- vector Bessel beam -- angular spectrum decomposition method -- dipole approximation -- beam polarization; Optics -- Periodicals; 535.05
• DOI: 10.1088/2040-8986/19/2/025602
• Languages: English
• ISSNs: 2040-8978

Abstract

Abstract: The effect of polarization on the optical spin torque (OST) exerted on an absorptive Rayleigh dielectric sphere by a vector Bessel beam is investigated using the dipole approximation method, with particular emphasis on the polarization of the plane wave component forming the beam. On the basis of the mathematical descriptions for the electric fields, which are derived using the angular spectrum decomposition method in plane waves, analytical formulas of the OST are established. The OSTs are numerically calculated, and the effects of polarization, beam-order, and half-cone angle are discussed in detail. Numerical results show that by choosing an appropriate polarization, order and half-cone angle, the transverse OST will manifest vortex-like behaviors, and the sphere will experience negative axial OSTs, i.e. OST sign reversal. Important applications in particle manipulation, rotation and handling using optical Bessel polarized beams would benefit from the results of the present investigation.