Manipulation of Metal Nanoparticles using Fiber-Optic Laser Tweezers with a Microspherical Focusing Lens

Abstract

This paper describes the laser manipulation of metal nanoparticles and dielectric particles by fiber-optic laser tweezers with a microspherical focusing lens. In this manner, a small ball lens attached to the end of the core focuses light guided through a single-mode optical fiber. Numerical electromagnetic analysis of the microfocusing structure showed the possibility of metal nanoparticle trapping with this method. An effective focus allows metallic particles located in the path of the focused light to be attracted to the center of the beam path and to be two-dimensionally trapped on a substrate. In the experiment, manipulation of Au nanoparticles with diameters of 40, 100, and 200 nm was demonstrated. In addition to metallic samples, manipulation of dielectric particles with 1 and 3 µm diameters was also demonstrated using the same configuration, showing the extended capability of the fiber-optic laser manipulator.