Inverse Microparticle Design for Enhanced Optical Trapping and Detection Efficiency in All Six Degrees of Freedom

TL;DR

This paper introduces a computational framework that designs microparticles with optimized geometries for improved optical trapping and detection in all six degrees of freedom, advancing levitated optomechanics.

Contribution

It presents a novel inverse design method combining electromagnetic scattering and the adjoint method to create particles with superior trapping and detection capabilities.

Findings

Optimized microparticle geometries enhance trapping efficiency.

Designed particles improve detection of translational and rotational motion.

Framework enables quantum-limited control in standard traps.

Abstract

Achieving quantum-limited motional control of optically trapped particles beyond the sub-micrometer scale is an outstanding problem in levitated optomechanics. A key obstacle is solving the light scattering problem and identifying particle geometries that allow stable trapping and efficient motional detection of their center of mass and rotational motion in three dimensions. Here, we present a computational framework that combines an efficient electromagnetic scattering solver with the adjoint method to inversely design printable microparticles tailored for levitated optomechanics. Our method allows identifying optimized geometries, characterized by enhanced optical trapping and detection efficiencies compared to conventional microspheres. This improves the feasibility of quantum-limited motional control of all translational and rotational degrees of freedom in a standard standing-wave optical trap.