Electromagnetically Induced Transparency (EIT) Amplitude Noise Spectroscopy

TL;DR

This paper explores how polarization-based intensity noise cross-correlation in atomic vapor cells can be used for high-resolution spectroscopy, magnetometry, and atomic coherence studies, revealing the stochastic nature of lightfield amplitude fluctuations.

Contribution

It demonstrates that varying the polarization basis enhances the probing of atomic states and links EIT noise to an underlying stochastic process in lightfield amplitudes.

Findings

Polarization basis variation improves atomic state probing.

Intensity noise can be modeled as a stochastic process.

Supports a simple atomic quantum optics model of EIT noise.

Abstract

Intensity noise cross-correlation of the polarization eigenstates of light emerging from an atomic vapor cell in the Hanle configuration allows one to perform high resolution spectroscopy with free- running semiconductor lasers. Such an approach has shown promise as an inexpensive, simpler approach to magnetometry and timekeeping, and as a probe of dynamics of atomic coherence in warm vapor cells. We report that varying the post-cell polarization state basis yields intensity noise spectra which more completely probe the prepared atomic state. We advance and test the hypothesis that the observed intensity noise can be explained in terms of an underlying stochastic process in lightfield amplitudes themselves. Understanding this stochastic process in the light field amplitudes themselves provides a new test of the simple atomic quantum optics model of EIT noise.