Atom-Based Microwave Sensing over 60 dB Dynamic Range

Detection of microwave (MW) field with high accuracy is an important problem in the physical science and engineering area. In this work, we reported an atomic Rabi resonance-based MW magnetic field sensor and demonstrated its capability to continuously detect X-band MW magnetic field over a high dynamic power range of > 60 dB. The MW power frequency shift was carefully evaluated and canceled in order to support more sensitive filed measurement. A weak 9.2 GHz MW magnetic field lower than 10 nT was successful extracted from Rabi resonance line on the cesium clock transition. MW field and power detection capabilities of the presented method can be extended to cover a higher dynamic range and a wider frequency band by applying stronger excitation and exploring non-clock atomic transition. Our work enables potential applications including SI-traceable MW calibration and atomic communication.