Rydberg atom-based microwave electrometry using polarization spectroscopy

TL;DR

This paper demonstrates enhanced microwave electric field measurement using Rydberg atom-based polarization spectroscopy in a vapor cell, achieving lower detection limits and improved field focusing with a custom lens.

Contribution

It introduces a polarization spectroscopy method for Rydberg atom electrometry that surpasses conventional EIT techniques and incorporates a microwave lens for field enhancement.

Findings

Minimum measurable microwave electric field is five times lower than traditional methods.

A custom microwave lens increases the field at the focus by a factor of three.

The experimental results align well with a comprehensive optical Bloch equation model.

Abstract

In this study, we investigated Rydberg atom-based microwave electrometry using polarization spectroscopy in a room-temperature vapor cell. By measuring Autler-Townes splitting in the electromagnetically induced transparency (EIT) spectrum, we determined that the minimum measurable microwave electric field is approximately five times lower than conventional EIT techniques. The results are well reproduced by a full optical Bloch equation model, which takes into account all the hyperfine levels involved. Subsequently, the EIT setup was used to characterize a custom microwave cylindrical lens, which increases the field at the focus by a factor of three, decreasing the minimum measurable microwave electric field by the same amount. Our results indicate that the combination of polarization spectroscopy and a microwave lens may enhance microwave electrometry.