Simulations of optical forces by a microstructured continuous superposition of first-order nonparaxial Bessel beams on Rayleigh particles

Abstract

This paper investigates optical forces on absorptive Rayleigh particles produced by a nondiffracting microstructured vectorial beam (micrometer Frozen Wave) designed from a continuous superposition of first-order Bessel beams, very adaptive to highly nonparaxial conditions. Carrying a non null topological charge and possessing a vector nature, these beams have both orbit and spin angular momentum. Thus, this paper aims to investigate the possibility of setting a Rayleigh particle to follow a circular or elliptical trajectory by these beams. Since energy considerations are also taken into account, optical forces can be conveniently expressed in femtonewtons. Numerical results demonstrate that the micrometer Frozen Wave is able to produce full three-dimensional optical trapping points, thus allowing the manipulation of several particles simultaneously. Additionally, those beams with circular (elliptical) polarization states are capable of setting the particle to follow a circular (elliptical) orbit around the optical axis.