Symmetry and the generation and measurement of optical torque

TL;DR

This paper explores how symmetries in particles and beams influence the creation and measurement of optical torque in optical tweezers, providing principles for designing optically-driven micromachines.

Contribution

It analyzes the role of symmetry in optical torque generation and measurement, offering new insights for designing micromachines using optical tweezers.

Findings

Symmetries significantly affect optical torque transfer.

Design principles for optically-driven micromachines are proposed.

Guidelines for optimizing optical trapping based on symmetry considerations.

Abstract

A key element in the generation of optical torque in optical traps, which occurs when electromagnetic angular momentum is transferred from the trapping beam to the trapped particle by scattering, is the symmetries of the scattering particle and the trapping beam. We discuss the effect of such symmetries on the generation and measurement of optical torque in optical tweezers, and some consequent general principles for the design of optically-driven micromachines.