基于里德堡原子EIT的微波电场感知

Microwave electric field sensing based on EIT of Rydberg atoms

基于里德堡原子电磁诱导透明(EIT)效应的微波电场感知是当前微波信号精密测量和成像领域的研究热点之一。分析了里德堡原子微波电场计的测量原理,介绍了腔内EIT效应增强的微波电场测量方案,光学腔耦合效应压窄光谱线宽,提高了系统的探测灵敏度和鲁棒性;介绍了基于双EIT效应的强度和频率感知微波电场的方法,利用双EIT系统干涉效应压窄光谱线宽,提高了测量精度,而且考虑原子气体多普勒效应后,微波电场的探测灵敏度提高了大约10倍;进一步分析了双EIT系统色散特性,发现暗态间相互作用可以显著提高EIT窗口处的色散,通过相位检测方法感知微波电场信号,具有信噪比高、灵敏度强等特点;最后,介绍了基于双EIT的微波电场非线性测量方案,双EIT系统干涉效应可以大大提高其光学非线性,非线性光谱线宽远小于线性情况,将最小可探测微波电场强度提高一个数量级以上,并用缀饰态理论很好地解释了光谱变化特性。

The microwave(MW)electric(E)field sensing based on the electromagnetically induced transparency(EIT)effect of Rydberg atoms is one of the hot topics in the field of microwave detection and imaging.The detection principle of MW E-field meter in Rydberg atoms was investigated and some effective schemes of MW E-field detection werere ported in this paper,Firstly,the coupling effect of an optical cavity could narrow the spectral linewidth and improve the sensitivity and robustness of the MW detection.Secondly,the scheme of frequency and intensity readout of MW E fields was introduced based on double EIT,whose interference effect narrowed the spectral linewidth and improved the measurement accuracy.Moreover,the atomic gas Doppler effect could increase the detection sensitivity by about ten times.By analyzing the dispersion characteristics of the double EIT system,it was found that the enhanced dispersion could be used for phase detection of MW fields,exhibiting high signal-to-noise ratio and sensitivity.Finally,a nonlinear measurement of MW fields based on double EIT was introduced.The interference effect of the double EIT system could significantly enhance the nonlinearity and narrow its linewidth.The minimum detectable MW E fields could be improved by up to single order magnitude and the spectral changes could be suitable realized with the dressed-state theory.