Time-average forces over Rayleigh particles by superposition of equal-frequency arbitrary-order Bessel beams

Abstract

We investigate optical forces exerted by suitable superpositions of equal-frequency Bessel beams—frozen waves—over dielectric, magnetodielectric, and negative-index Rayleigh particles. Frozen waves are capable of providing virtually any desired longitudinal intensity pattern by adequately superposing arbitrary-order Bessel beams, serving as potential beams in optical trapping, atom guiding, optical bistouries, and so on. Analytical expressions for gradient and scattering forces experienced by very small particles are deduced, and our numerical examples reveal that both low- and high-index dielectric and magnetodielectric particles can be efficiently trapped and manipulated. Our results indicate that such wave fields could actually provide three-dimensional traps in multiple transverse planes.