Open AccessGradient forces on double-negative particles in optical tweezers using Bessel beams in the ray optics regime
Author(s) -
Leonardo André Ambrosio,
H.E. Hernández-Figueroa
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.024287
Subject(s) - optical tweezers , refractive index , optics , physics , optical force , bessel function , geometrical optics , dielectric , sign (mathematics) , particle (ecology) , x ray optics , pressure gradient force , tweezers , x ray , quantum mechanics , mathematical analysis , oceanography , mathematics , geology
Gradient forces on double negative (DNG) spherical dielectric particles are theoretically evaluated for v-th Bessel beams supposing geometrical optics approximations based on momentum transfer. For the first time in the literature, comparisons between these forces for double positive (DPS) and DNG particles are reported. We conclude that, contrary to the conventional case of positive refractive index, the gradient forces acting on a DNG particle may not reverse sign when the relative refractive index n goes from |n|>1 to |n|<1, thus revealing new and interesting trapping properties.