Structured-Light Magnetometry in a Coherently Controlled Atomic Medium

TL;DR

This paper introduces a novel structured-light method for magneto-optical rotation detection, mapping polarization rotation onto a spatial pattern for direct, polarizer-free magnetic field sensing.

Contribution

It demonstrates converting polarization-based magnetometry into a spatially resolved topology-based approach using structured light and cold atom interactions.

Findings

Spatially resolved magnetic field measurement demonstrated.

Rotation angle extracted from interference pattern displacement.

Method eliminates the need for polarizers or Stokes analysis.

Abstract

A structured-light-based approach for detecting magneto-optical rotation is presented, in which polarization rotation is mapped onto a directly observable spatial degree of freedom. A radially polarized Laguerre-Gaussian beam interacts with cold $^{87}\mathrm{Rb}$ atoms in the presence of a longitudinal magnetic field, where magnetically induced circular birefringence introduces a relative phase shift between the $\sigma_+$ and $\sigma_-$ components of the field, manifesting as a rotation of the interference pattern. The MOR angle is extracted directly from the angular displacement of the petal-shaped intensity distribution, eliminating the need for polarizers or Stokes-parameter analysis. This method converts conventional polarization-based magnetometry into a topology-based spatial readout, enabling spatially resolved magnetic-field sensing with potential applications in optical magnetometry and quantum sensing.