Abstract
We have theoretically and experimentally studied the dispersive signal of the Rydberg atomic electromagnetically-induced transparency(EIT)Autler-Townes(AT)splitting spectra obtained using amplitude modulation of the microwave(MW)electric field.In addition to the two zero-crossing points interval △fzeros,the dispersion signal has two positive maxima with an interval defined as the shoulder interval △fsho,which is theoretically expected to be used to measure a much weaker MW electric field.The relationship of the MW field strength EMW and △fsho is experimentally studied at the MW frequencies of 31.6 GHz and 9.2 GHz respectively.The results show that △fsho can be used to characterize the much weaker EMW than that of △fzeros and the traditional EIT-AT splitting interval △fm;the minimum EMW measured by△fsho is about 30 times smaller than that by △fm.As an example,the minimum EMW at 9.2 GHz that can be characterized by △fsho is 0.056 mV/cm,which is the minimum value characterized by the frequency interval using a vapor cell without adding any auxiliary fields.The proposed method can improve the weak limit and sensitivity of EMW measured by the spectral frequency interval,which is important in the direct measurement of weak EMW.
基金项目
北京市自然科学基金(1212014)
国家重点研发计划(2017YFA0304900)
国家重点研发计划(2017YFA0402300)
国家自然科学基金(11604334)
国家自然科学基金(11604177)
国家自然科学基金(U2031125)
中国科学院重点研究项目(XDPB08-3)
Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(KF201807)
中央高校基本科研业务费专项()
中国科学院青年创新促进会项目()
NETL
NSTL
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