Continuous broadband Rydberg receiver using AC Stark shifts and Floquet States

TL;DR

This paper presents a continuous broadband Rydberg-based microwave receiver that uses AC Stark shifts and Floquet states to achieve over 1.172 GHz of frequency coverage with high sensitivity, advancing applications in radar and wireless communication.

Contribution

The work introduces a novel Rydberg receiver design utilizing AC Stark shifts and Floquet states for continuous broadband microwave detection, with improved sensitivity through Floquet sideband coupling.

Findings

Achieved over 1.172 GHz continuous microwave frequency range.

Sensitivity of 280.2 nV/cm/Hz^{1/2} without RF field, improved via Floquet sidebands.

Demonstrated potential for radar and wireless communication applications.

Abstract

We demonstrate the continuous broadband microwave receivers based on AC Stark shifts and Floquet States of Rydberg levels in a cesium atomic vapor cell. The resonant transition frequency of two adjacent Rydberg states 78$S_{1/2}$ and 78$P_{1/2}$ is tuned based on AC Stark effect of 70~MHz Radio frequency (RF) field that is applied outside the vapor cell. Meanwhile, the Rydberg states also exhibit Floquet even-order sidebands that are used to extend the bandwidths further. We achieve microwave electric field measurements over 1.172~GHz of continuous frequency range. The sensitivity of the Rydberg receiver with heterodyne technique in the absence of RF field is 280.2~nVcm$^{-1}$Hz$^{-1/2}$, while it is dramatically decreased with tuning the resonant transition frequency in the presence of RF field. Surprisingly, the sensitivity can be greatly improved if the microwave field couples the Floquet sideband transition. The achieving of continuous frequency and high sensitivity microwave detection will promote the application of Rydberg receiver in the radar technique and wireless communication.