Gradient forces on double-negative particles in optical tweezers using Bessel beams in the ray optics regime

Author(s)

Ambrosio, Leonardo A. ^[1] ; Hernandez-Figueroa, Hugo E. ^[1]

Affiliation

^[1] Univ Campinas Unicamp, Sch Elect & Comp Engn FEEC, Dept Microwave & Opt DMO, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Optics Express; v. 18, n. 23, p. 24287-24292, NOV 8 2010.
• Web of Science Citations: 24

Abstract

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 vertical bar n vertical bar > 1 to vertical bar n vertical bar < 1, thus revealing new and interesting trapping properties. (C) 2010 Optical Society of America (AU)

• FAPESP's process: 05/51689-2 - Optics and Photonics Research Center at UNICAMP
• Grantee: Hugo Luis Fragnito
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC