Intensity correlations in resonance nonlinear magneto-optical rotation

TL;DR

This study investigates how intensity correlations between orthogonal polarization components of a laser beam change with magnetic field in a rubidium vapor, revealing insights for enhancing optical magnetometers and spin squeezing techniques.

Contribution

The paper presents experimental analysis of polarization component correlations in a resonant atomic medium under magnetic fields, linking correlation behavior to atomic and optical parameters.

Findings

Correlations are maximal without magnetic field.

Correlation magnitude varies non-monotonically with magnetic field.

Correlation width relates to excited state lifetime and Rabi frequency.

Abstract

We have studied the intensity correlations between two orthogonally linearly polarized components of a laser field propagating through a resonant atomic medium. These experiments have been performed in a Rubidium atomic vapor. We observe that the correlations between the orthogonally polarized components of the laser beam are maximal in the absence of a magnetic field. The magnitude of the correlations depends on the applied magnetic field, and the magnitude first decreases and then increases with increasing magnetic field. Minimal correlations and maximal rotation angles are observed at the same magnetic fields. The width of the correlation function is directly proportional to the excited state lifetime and inversely proportional to the Rabi frequency of laser field. These results can be useful for improving optical magnetometers and for optical field or atomic spin squeezing.