Mass and Shape Determination of Optically Levitated Nanoparticles

TL;DR

This paper presents a combined method for determining the mass and shape of optically levitated nanoparticles, enabling more precise characterization crucial for advanced sensing and measurement applications.

Contribution

It introduces a novel integrated approach combining charge-based mass measurement with light scattering and damping analysis for asymmetric nanoparticles.

Findings

Successfully distinguishes particles with similar mass but different shapes

Demonstrates combined method's effectiveness on silica nanoparticles

Enhances nanoparticle characterization for precision experiments

Abstract

When introducing a nanoparticle into an optical trap, its mass and shape are not immediately apparent. We combine a charge-based mass measurement with a shape determination method based on light scattering and an analysis of the damping rate anisotropy, all on the same set of silica nanoparticles, trapped using optical tweezers in vacuum. These methods have previously only been used separately, and the mass determination method has not been applied to asymmetric particles before. We demonstrate that the combination of these classification techniques is required to distinguish particles with similar mass but different shape, and vice versa. The ability to identify these parameters is a key step for a range of experiments on precision measurements and sensing using optically levitated nanoparticles.