Axial superlocalization with vortex beams

TL;DR

This paper explores the limits of axial localization precision in 3D optical imaging using vortex beams, highlighting how different beam types affect measurement accuracy and suggesting improvements for microscopy techniques.

Contribution

It demonstrates the ultimate axial localization precision achievable with vortex beams and identifies the advantages of mode-sorting over intensity scans for certain beam superpositions.

Findings

Laguerre-Gauss beams reach the axial localization limit with simple intensity scans.

Superpositions of Laguerre-Gauss beams require advanced mode-sorting for optimal precision.

Rotating vortex beams can enhance microscopy methods by replacing traditional sensors.

Abstract

Improving axial resolution is of paramount importance for three-dimensional optical imaging systems. Here, we investigate the ultimate precision in axial localization using vortex beams. For Laguerre-Gauss beams, this limit can be achieved with just an intensity scan. The same is not true for superpositions of Laguerre-Gauss beams, in particular for those with intensity profiles that rotate on defocusing. Microscopy methods based on rotating vortex beams may thus benefit from replacing traditional intensity sensors with advanced mode-sorting techniques.