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Updated: Jun 14, 2026

Optical Trapping of Nanoparticles
Published on: January 15, 2013
Bipolar optical forces on dielectric and metallic nanoparticles by evanescent wave
1Department of Electronic and Information Engineering and Key Laboratory of Network Oriented Intelligent Computation, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China. eiexiao@hitsz.edu.cn
Abstract:
We numerically show that both repulsive and attractive (bipolar) optical forces can be exerted on a dielectric or metallic cylindrical nanoparticle by a totally internal refracted wave. This requires that the particles possesses either a whispering gallery (WG) resonance or a localized surface plasmon (LSP) resonance. We further explore the force spectrum that is governed by competition between the separation-dependent resonant Q factor and the coupling strength of the nanoparticle to the evanescent wave. In spite of a much smaller Q of the LSP as compare to the WG resonances, the metallic particle gains much stronger trapping force.
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