Theoretical Analysis of Heterodyne Rydberg Atomic Receiver Sensitivity Based on Transit Relaxation Effect and Frequency Detuning

TL;DR

This paper provides a theoretical analysis of how detuning and transit relaxation affect the sensitivity of heterodyne Rydberg atomic receivers, showing potential for enhanced detection of weak microwave signals.

Contribution

It introduces a theoretical framework analyzing the effects of detuning and transit relaxation on receiver sensitivity, offering insights for optimizing Rydberg atomic sensor performance.

Findings

Laser and microwave detuning improve detection sensitivity.

The receiver can detect weak signals over a wide frequency range.

Transit relaxation reduces sensitivity and delays steady-state achievement.

Abstract

We conduct a theoretical investigation into the impacts of local microwave electric field frequency detuning, laser frequency detuning, and transit relaxation rate on enhancing heterodyne Rydberg atomic receiver sensitivity. To optimize the output signal amplitude given the input microwave signal, we derive the steady-state solutions of the atomic density matrix. Numerical results show that laser frequency detuning and local microwave electric field frequency detuning can improve the system detection sensitivity, which can help the system achieve extra sensitivity gain. It also shows that the heterodyne Rydberg atomic receiver can detect weak microwave signals continuously over a wide frequency range with the same sensitivity or even more sensitivity than the resonance case. To evaluate the transit relaxation effect, a modified Liouville equation is used. We find that the transition relaxation rate increases the time it takes to reach steady state and decreases the sensitivity of the system detection.