We report on a global crossover saturated-absorption spectroscopy (SAS) of Cs D 2 transition using a dual-frequency laser field with a frequency difference of less than the Doppler width. With two pairs of dual-frequency laser beams counter-propagating through the vapor cell, the line shape and non-linear features observed in the transmission spectra of the probe beam change with the frequency difference of the dual-frequency laser. The superficially complicated transmission signal includes two sets of common single-frequency SAS and several velocity-selective resonances (VSRs), we call these VSR peaks ‘global crossover SAS’. This phenomenon is explained by VSR effect. The global crossover SAS is formed by the atomic velocity groups resonance with both the initial and modulated laser fields, which are counter-propagated. Moreover, the global crossover SAS dips having the separation of allowed hyperfine transitions move along with the two sets of common single-f...

中文翻译：

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双频激光诱导的全局交叉饱和吸收光谱

我们报告了使用具有小于多普勒宽度的频率差的双频激光场的Cs D 2跃迁的全球交叉饱和吸收光谱（SAS）。通过两对双频激光束反向传播通过蒸气室，探测光束的透射光谱中观察到的线形和非线性特征随双频激光的频率差而变化。表面复杂的传输信号包括两组常见的单频SAS和几个速度选择共振（VSR），我们将这些VSR峰称为“全局交叉SAS”。VSR效应解释了这种现象。全局交叉SAS由与初始和调制激光场共振的原子速度群共振形成，它们反向传播。此外，