Regular Article

Nanometric plasmonic optical trapping on gold nanostructures

Laboratory of “Optoelectronics, Lasers and their Applications”, Physics Department, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece

^* e-mail: dkotsifaki14@gmail.com

Received: 2 December 2018
Received in final form: 1 March 2019
Accepted: 13 June 2019
Published online: 30 July 2019

Abstract

The precise noninvasive optical manipulation of nanometer-sized particles by evanescent fields, instead of the conventional optical tweezers, has recently awaken an increasing interest, opening a way for investigating phenomena relevant to both fundamental and applied science. In this work, the optical trapping force exerted on trapped dielectric nanoparticle was theoretically investigated as a function on the trapping beam wavelength and as a function of several plasmonic nanostructures schemes based on numerical simulation. The maximum optical trapping forces are obtained at the resonance wavelength for each plasmonic nanostructure geometry. Prominent tunabilities, such as radius and separation of gold nanoparticles as well as the numerical aperture of objective lens were examined. This work will provide theoretical support for developing new types of plasmonic sensing substrates for exciting biomedical applications such as single-molecule fluorescence.