Optical Trapping of Large Metallic Particles in Air

TL;DR

This paper presents a novel photophoretic optical trap capable of capturing and holding large metallic gold particles in air for extended periods, enabling new studies of plasmonic particles.

Contribution

Introduction of a horizontally-oriented, self-loading photophoretic trap for large metallic particles, with demonstrated stability and adjustable scanning capabilities.

Findings

Successfully trapped gold particles for over an hour

Demonstrated axial scanning and size expansion of the trap

Potential applications in studying plasmonic particles

Abstract

In this paper, we introduce a horizontally-oriented, photophoretic `boat' trap that is capable of capturing and self-loading large (radius ${\ge}1$ $\mu$m) solid gold particles in air for more than one hour. Once trapped, particles are held stably, even as the trap is modified to scan axially or expanded to a larger size to increase the capture cross-section. We theoretically present and experimentally demonstrate each of these affordances. We describe the utility of such to investigate large, metallic, and plasmonic particles for display applications.