| 摘要: |
| 基于高激发里德堡原子的微波电场测量技术与传统金属天线相比有诸多优越性，是未来微波电场高精度测量的重要方案之一。采用全红外光激发里德堡原子的方案不再依赖复杂而昂贵的短波长激光器，大大减小了激光器系统的体积与能耗。在三红外光级联激发里德堡铷原子的过程中，发现了中间态对应的双光梯形电磁诱导透明光学参数对三光激发里德堡态电磁诱导吸收峰信噪比具有重要影响，因此采用光失谐方法能很好地优化三光EIA光谱。利用微波场下的Autler-Townes分裂效应和标准天线方法对微波喇叭天线发射的微波电场实现精确的校准，并以此为基础通过超外差接收技术成功探测到本地场与信号场所形成的拍频信号，得到了拍频光电信号与信号场强度之间的线性关系。最终通过实验噪声基底的噪声功率谱得到三红外光里德堡铷原子微波测量的极限灵敏度为37.5(5.5) nV·cm－1/Hz。采用三束红外光激发的方法为研制小型里德堡原子微波电场探测仪器奠定了物理基础。 |
| 关键词: 里德堡原子 电磁诱导透明（吸收） 微波电场强度测量 超外差接收 |
| DOI： |
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| 基金项目:国家重点研发计划(2021YFF0603704)；国家自然科学基金(12074388，12004393) |
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| Microwave electric field measurement based on Rydberg atoms excited by all infrared lasers |
| YOU Shuhang,CAI Minghao,ZHANG Haoan,LIU Hongping |
| (Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430071, China) |
| Abstract: |
| Based on the highly excited Rydberg atoms, the microwave electric field intensity measurement technology is more advantageous to the one measured by conventional metal antenna, which is one of most significant strategies in microwave (MW) electric field intensity measurement. The scheme that Rydberg atoms are excited by all infrared lights minishes the volume and power dissipation of the system, without the dependence on intricate and expensive short-wavelength lasers. In the course of the cascade excitation of Rydberg Rb atoms by three infrared lasers, the optical parameters of the two-laser ladder electromagnetic induced transparency corresponding to the intermediate state have an enormous influence on the signal-to-noise ratio of the three-laser electromagnetic induced absorption spectrum peak of the Rydberg atoms excited by three lights. Hence the EIA spectroscopy can be optimized by the method of laser detuning. The microwave field transmitted by the microwave horn antenna is calibrated precisely using the Aulter-Townes splitting effect and standard antenna method, based on which the beat signals formed by local MW and signal MW are successfully detected via superheterodyne receive technology. The linear relationship between the beat photoelectric signal and the electric field intensity of signal MW also is obtained. Ultimately,with the noise power spectrum of noise base in the experiment, the limit sensitivity of the three infrared lasers Rydberg Rb atoms microwave measurement is 37.5(5.5) nV·cm－1/Hz. This method paves the way to realize the miniaturized Rydberg atoms microwave detector. |
| Key words: Rydberg atoms Electromagnetic induced transparency (absorption) Microwave electric field intensity measurement Superheterodyne receiver |
