Imaginary Poynting forces on a magnetodielectric particle under cylindrical vector lights

Abstract

Particles with magnetodielectric dual responses endure the unique imaginary Poynting force, attributed to the crossed interference between electric and magnetic dipoles. In this work, we theoretically demonstrate that for illumination of cylindrical vector light with azimuthal or radial polarization, the imaginary Poynting force has a radial diffusion or centripetal trapping characteristic exerted on a magnetodielectric particle. Moreover, with a superposition of linearly-polarized light on the cylindrical vector light, an extra transverse force will emerge with a unidirectional characteristic. Our work reveals the unique role of imaginary Poynting force for optical manipulations on magnetodielectric particles by cylindrical vector lights, including radial diffusion, centripetal trapping, and transverse conveying.