Measurement of single nanoparticle anisotropy by laser induced optical alignment and Rayleigh scattering for determining particle morphology

TL;DR

This paper presents a novel optical method to determine nanoparticle shape and anisotropy by analyzing Rayleigh scattering of levitated particles, enabling high-resolution shape discrimination in vacuum and fluid environments.

Contribution

The study introduces a new technique combining laser-induced optical alignment and Rayleigh scattering for nanoparticle shape measurement, capable of resolving nanometer-scale differences.

Findings

Effective shape discrimination down to a few nanometers.

Applicable in vacuum and fluid environments.

Demonstrated on various nanoparticle geometries.

Abstract

We demonstrate the measurement of nanoparticle shape by angularly resolved Rayleigh scattering of single optical levitated particles that are oriented in space via the trapping light in vacuum. This technique is applied to a range of particle geometries, from perfect spherical nanodroplets to octahedral nanocrystals. We show that this method can resolve shape differences down to a few nanometers and be applied in both low-damping environments, as demonstrated here, and in traditional overdamped fluids used in optical tweezers.