Radiation forces on a Rayleigh particle by a highly focused elliptically polarized beam

The radiation force of highly focused elliptically polarized beams on a Rayleigh particle is theoretically studied. The numerical results show that elliptically polarized beams can be used to trap particles. The influence of the beam widths, phase retardations of the incident beam, and numerical apertures of an objective lens on the radiation force distribution has been studied. Studies in transverse scattering forces reveal that torques can be produced by elliptically polarized beams carrying spin angular momentum, and that the torque, in the focal plane, produced by elliptically polarized beams can be regarded as the superposition of those by right-hand circularly and left-hand circularly polarized beams with different ratios between them.