基于里德堡原子外差传感器的宽带高灵敏探测  

Broadband and Highly Sensitive Measurement Based on Rydberg Atomic Heterodyne Sensor

作　　者：杨凯 毛瑞棋 孙占山 李健兵 付云起[1] Yang Kai;Mao Ruiqi;Sun Zhanshan;Li Jianbing;Fu Yunqi(College of Electronic Science and Technology,National University of Defense Technology,Changsha 410073,Hunan,China;State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System,National University of Defense Technology,Changsha 410073,Hunan,China)

机构地区：[1]国防科技大学电子科学学院,湖南长沙410073 [2]国防科技大学电子信息系统复杂电磁环境效应国家重点实验室,湖南长沙410073

出　　处：《光学学报》2023年第17期268-274,共7页Acta Optica Sinica

基　　金：国家自然科学基金(12104509);国防科技大学自主科研资助项目(ZK22-59)。

摘　　要：里德堡原子外差技术通过引入辅助本振场可以极大地提升探测灵敏度,在雷达、电子侦察和通信方面具有广阔的应用潜力。本文在一个2 cm长的室温铯原子气室中,利用相向传输的探测光(852 nm)和耦合光(509 nm)将铯原子激发至里德堡态,用于实现里德堡原子光学探测。实验中分别用喇叭天线和平行板波导作为谐振区和非谐振区的微波发射装置,利用里德堡原子外差技术,实现了谐振区2.63 GHz处最小场强为220.94 nV/cm和非谐振区300 MHz处最小场强为19μV/cm的微波电场测量,测量灵敏度分别为-131.9(dBm/cm2)/Hz和-93.2(dBm/cm^(2))/Hz。原则上,通过调谐激光频率激发碱金属原子至不同的里德堡态,并结合谐振区和非谐振区里德堡原子对电场的不同响应,可以在宽带连续频谱范围内实现对微波电场的高灵敏度探测。Objective Rydberg atoms became increasingly crucial in the last decade because of their fascinating characteristics that distinguish them from conventional radio frequency(RF)sensors.First,the Rydberg atoms are self-calibrating thanks to the invariance of the atomic parameters,and their response is linked to Plank's constant.Second,atomic sensing systems break a key assumption behind the Chu limit of traditional electronic sensors by allowing a small vapor cell to operate over multiple octaves of frequencies from DC to THz.Third,instead of demodulated circuitry,Rydberg atoms can naturally extract the baseband signals from the carrier frequency.Fourth,Rydberg atoms may avoid internal thermal(Johnson)noise,even at room temperature.In recent years,the amazing introduction of the local oscillator(LO)RF field has assisted us in controlling ensembles of Rydberg atoms.However,most current reports on Rydberg atomic heterodyne sensors focus on measurements in the resonant region,which can only achieve highly sensitive detection at discrete frequencies due to the quantum nature of the atomic energy level.In this work,by extending the Rydberg atomic heterodyne technique from the resonant region to the off-resonant region,we experimentally validated the continuous broadband and high sensing sensitivity of Rydberg atoms.Methods When a strong LO field and a weak signal(SIG)field with frequency detuning on the order of kHz are irradiated to the atoms,the energy level will be modulated by the intermediate frequency(IF)in the resonant and off-resonant regions,which can be directly detected by optical electromagnetically induced transparency(EIT).At room temperature,a probe laser of 852 nm and a coupling laser of 509 nm propagate in opposite directions and overlap inside a 2 cm-long vapor cell containing cesium atoms,exciting the atoms to the Rydberg state for atomic sensing.In the resonant region,the LO frequency is set to 2.63 GHz,and the SIG frequency is set to 2.63 GHz+10 kHz.Both fields are illuminated into the vapor cell by

关 键 词：遥感与传感器 里德堡原子 外差技术 宽带 电场强度测量 

分 类 号：O439[机械工程—光学工程]