Multiple optical trapping based on high-order axially symmetric polarized beams*
Zhou Zhe-Hai†, Zhu Lian-Qing
       
Gradient forces produced by tightly focused ASPBs on spherical dielectric particles, where (a) gradient force along the x axis at focus and (b) along the z axis through focus. The refractive indices of the particles and the ambient are 1.60 and 1.33 respectively, and the polarization orders of ASPBs are 6, 10, and 16 respectively.