Cavity-enhanced microwave electric field measurement using Rydberg atoms

Abstract

An enhanced measurement of the microwave electric (MW E) field by using intracavity Rydberg atoms is proposed. Based on electromagnetically induced transparency (EIT), the intracavity atomic system exhibits two EIT windows, resulting in two narrow peaks in the cavity transmission. The peak-to-peak distance is sensitive to MW fields and can be used to probe MW E-field strength. Simulation results show that the detectable minimum strength of the MW fields is nearly eight times smaller than that without a cavity. Due to cavity coupling, the transmission spectrum is greatly narrowed, which improves the measurement resolution substantially. The numerical results show that the spectrum resolution is increased by more than 20 times. Furthermore, the cavity-enhanced measurement scheme seems to be robust against the changes in the control field strength and shows a broadband tunability.