Realizing optical pulling force using chirality

TL;DR

This paper derives an analytical formula showing how chiral particles experience unique optical forces, enabling optical pulling forces through chirality-induced coupling between momentum and spin angular momentum.

Contribution

It introduces a new analytical model for optical forces on chiral particles, revealing chirality-dependent mechanisms for optical pulling forces.

Findings

Chiral particles exhibit different optical force behaviors than achiral ones.

Chirality induces coupling between linear momentum and optical spin angular momentum.

Numerical simulations confirm the analytical predictions.

Abstract

We derived an analytical formula for the optical force acting on a small anisotropic chiral particle. The behavior of chiral particles is qualitatively different from achiral particles due to new chirality dependent terms which couple mechanical linear momentum and optical spin angular momentum. Such coupling induced by chirality can serve as a new mechanism to achieve optical pulling force. Our analytical predictions are verified by numerical simulations.