Non-destructive Faraday imaging of dynamically controlled ultracold atoms

TL;DR

This paper presents a simple, non-destructive Faraday imaging method for ultracold atoms that allows repeated measurements of the same cloud, enabling detailed static and dynamic property analysis with minimal disturbance.

Contribution

The authors introduce a dark field Faraday imaging technique that achieves high sensitivity and low destructiveness, allowing multiple images of the same ultracold atomic cloud in a single experimental run.

Findings

Spatially resolved images can be acquired up to 2000 times from the same cloud.

The sensitivity matches conventional dispersive imaging techniques in ideal conditions.

The method enables single-run vector magnetic field and dynamic behavior imaging.

Abstract

We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration, to demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. This demonstrates that the method is a useful tool for the characterization of static and dynamically changing properties of ultracold atomic clouds.