Rotating polarization magnetometry

TL;DR

This paper introduces a rotating polarization technique in optical atomic magnetometry that maintains high sensitivity over a broader magnetic field range by avoiding alignment-to-orientation conversion, surpassing previous NMOR methods.

Contribution

The study demonstrates that using continuously rotating linear polarization enhances magnetometric sensitivity and dynamic range, challenging prior assumptions about AOC's role in sensitivity loss.

Findings

Achieved high sensitivity over nearly three times Earth's magnetic field.

Rotating polarization outperforms modulated light NMOR techniques.

Signal deterioration is not caused by AOC, indicating alternative factors.

Abstract

Precise magnetometry is vital in numerous scientific and technological applications. At the forefront of sensitivity, optical atomic magnetometry, particularly techniques utilizing nonlinear magneto-optical rotation (NMOR), enables ultraprecise measurements across a broad field range. Despite their potential, these techniques reportedly lose sensitivity at higher magnetic fields, which is attributed to the alignment-to-orientation conversion (AOC) process. In our study, we utilize light with continuously rotating linear polarization to avoid AOC, producing robust optical signals and achieving high magnetometric sensitivity over a dynamic range nearly three times greater than Earth's magnetic field. We demonstrate that employing rotating polarization surpasses other NMOR techniques that use modulated light. Our findings also indicate that the previously observed signal deterioration is not due to AOC, suggesting an alternative cause for this decline.