Microstructured Light Fields for Optical Trapping: Zero Order Continuous Vector Frozen Waves in the Rayleigh Regime

摘要

This paper investigates, for the first time in the literature, the optical forces exerted by a new class of non-diffracting beams on Rayleigh (dipole) scatterers, envisioning applications e.g. in optical trapping and micromanipulation, atom guiding, particle sorting and so on. Such microstructured light fields can be designed to provide a wide variety of longitudinal intensity patterns along the optical (longitudinal) axis and on the micrometer scale, being constructed from a continuous superposition of Bessel beams. Coined 'continuous vector Frozen Waves' (CVFWs), here we focus on their linear polarized zero-order versions, studying radial and longitudinal optical forces in situations involving different paraxiality conditions, including absorbing characteristics and distinct refractive indices of the scatterers. Power requirements reveal that the strength and spatial profile of the optical forces here found are within those expected for an effective trapping and manipulation of very small dielectric particles.