Single-Photon-Level Sub-Doppler Pump-Probe Spectroscopy of Rubidium
Single-Photon-Level Sub-Doppler Pump-Probe Spectroscopy of Rubidium
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DOI：
10.1103/physrevapplied.14.044046
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发表时间：
2020-07
期刊：
影响因子：
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通讯作者：
P. Burdekin;S. Grandi;Rielly Newbold;R. Hoggarth;K. D. Major;A. Clark
中科院分区：
文献类型：
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作者：
P. Burdekin;S. Grandi;Rielly Newbold;R. Hoggarth;K. D. Major;A. Clark
我们提出并证明了铷原子吸收的泵浦-探测光谱，它揭示了$^{5}$S$_{1/2} \leftrightarrow$ $^{5}$P$_{3/2}$（D2）跃迁的亚多普勒超精细结构。反向传播的泵浦和探测激光器的频率是独立可调的，探测器工作在单光子水平。扫描激光频率时测得的二维光谱显示出荧光、多普勒展宽吸收下降和亚多普勒特征。泵浦和探测激光器之间的失谐允许补偿室温蒸气中所有原子速度的多普勒频移，这意味着我们观察到光束中所有原子的亚多普勒特征。我们详细介绍了一个理论模型的系统，其中包括荧光，饱和效应和光泵，并与测量光谱进行比较，发现平均绝对百分比误差为4.17%。在未来，这种技术可以帮助激光器的频率稳定，单光子探测器可以被单光子源取代。
We propose and demonstrate pump-probe spectroscopy of rubidium absorption which reveals the sub-Doppler hyperfine structure of the $^{5}$S$_{1/2} \leftrightarrow$ $^{5}$P$_{3/2}$ (D2) transitions. The counter propagating pump and probe lasers are independently tunable in frequency, with the probe operating at the single-photon-level. The two-dimensional spectrum measured as the laser frequencies are scanned shows fluorescence, Doppler-broadened absorption dips and sub-Doppler features. The detuning between the pump and probe lasers allows compensation of the Doppler shift for all atomic velocities in the room temperature vapor, meaning we observe sub-Doppler features for all atoms in the beam. We detail a theoretical model of the system which incorporates fluorescence, saturation effects and optical pumping and compare this with the measured spectrum, finding a mean absolute percentage error of 4.17\%. In the future this technique could assist in frequency stabilization of lasers, and the single-photon-level probe could be replaced by a single photon source.