Radiation force acting on a Rayleigh dielectric sphere produced by Whittaker-Gaussian beams

Optical trapping and manipulating of micro particles have attracted extensive interests due to the advantages of being noncontact and noninvasive. In this work, the field distribution of Whittaker-Gaussian (WG) beams propagating through a lens and the radiation force acting on the Rayleigh particle are investigated numerically and theoretically. The results show that the WG beams can trap the particles with both high and low index of refractive near the focus. The influences of optical parameters on the radiation forces are analyzed in detail. Furthermore, the conditions for trapping stability are also discussed.