Optically induced sieve effect for nanoparticles near a nanofiber taper

TL;DR

This paper demonstrates a passive, mode-based optical trapping technique that selectively traps and transports nanoparticles of different sizes near a nanofiber taper, enabling a sieve-like separation effect.

Contribution

It introduces a novel size-selective optical trapping method using a two-wavelength, counter-propagating mode configuration near a nanofiber taper.

Findings

100 nm and 150 nm gold nanospheres are trapped at different powers

Selective trapping allows transport of one nanoparticle species while trapping the other

Mode behavior in nanophotonics enables sophisticated optical manipulation

Abstract

We demonstrate size selective optical trapping and transport for nanoparticles near an optical nanofiber taper. Using a two-wavelength, counter-propagating mode configuration, we show that 100 nm diameter and 150 nm diameter gold nanospheres (GNSs) are trapped by the evanescent field in the taper region at different optical powers. Conversely, when one nanoparticle species is trapped the other may be transported, leading to a sieve-like effect. Our results show that sophisticated optical manipulation can be achieved in a passive configuration by taking advantage of mode behavior in nanophotonics devices.