Apply Non-Hermitian Physics to Realize Ultra-High-Quality Factors of Optically Trapped Particles

TL;DR

This paper explores how non-Hermitian physics can be applied to optical trapping systems to achieve ultra-high-quality factors by balancing energy input and dissipation, revealing strategies for optimizing force fields.

Contribution

It demonstrates the application of non-Hermitian physics to optical trapping, showing how to enhance quality factors through parameter tuning and lattice design.

Findings

Non-Hermitian forces can induce stable vibrations with high Q-factors.

Increasing particle size and refractive index improves non-Hermitian force effects.

Lattice design strategies can optimize energy pumping and dissipation balance.

Abstract

Optical trapping and binding systems are non-Hermitian. On one hand, the optical force is non-Hermitian and may pump energy into the trapped particle when the non-Hermiticity is sufficiently large. On the other hand, the ambient damping constitutes a loss to the particle. Here, we show that in a low-friction environment, the interplay between the energy pumped-in by light and the ambient dissipation can give rise to either instability or a periodic vibration characterized by a finite quality factor (Q-factor). Through a comprehensive exploration, we analyze the influence of various parameters on the non-Hermitian force field. Our investigation reveals several strategies for enhancing the non-Hermitian force field, such as augmenting particle radius and refractive index, utilizing triangular lattice optical clusters, and reducing lattice constants.