Optical spectral features and electric field inversion method for Rydberg atoms under ultra-low frequency electric field

The quantum measurement of the microwave electric field based on Rydberg atoms developed in recent years has shown promise for enhancing accuracy, sensitivity and stability. However, the study of ultra-low frequency electric field measurements in power systems is still in its early stages, presenting new challenges for Rydberg-based measurement techniques. In this work, a ladder-type two-photon three-level structure of Cs atoms is selected, and the corresponding experimental system is constructed. Two kinds of laser control schemes, which are referred to as mismatch and match measurement schemes, are then proposed, and the quantum effect’s optical spectrum is obtained by using the two measurement schemes. After these measured spectral properties are compared, the match measurement scheme is chosen for real-time measurement of ultra-low frequency electric fields. Additionally, dynamic models of the interactions among the laser field, ultra-low frequency electric field and atoms are derived, on the basis of which theoretical simulations are being conducted to study the effects of the input parameters of the electric field and laser power on the optical spectrum. On the basis of the optical spectral features, an inversion method for the excitation electric field in real time is proposed, and its effectiveness is demonstrated.