铯原子6S_(1/2)-6P_(1/2)-8S_(1/2)阶梯型系统中的电磁感应透明信噪比的提高

Improvement of Signal-to-Noise Ratio of Electromagnetically-Induced Transparency Spectra in the Ladder-Type Cesium 6S_(1/2)-6P_(1/2)-8S_(1/2)Atomic System

为了获得高信噪比的电磁感应透明(EIT)谱线,对铯原子6S1/2-6P1/2-8S1/2阶梯型能级系统的EIT谱进行了研究。探测光的频率锁定于基态到中间态的超精细跃迁线上,控制光在中间态到激发态超精细跃迁线之间扫描,得到的EIT谱具有平坦的背景,提高了光谱的信噪比。阶梯型能级系统中光谱信号强度不仅与控制光束和探测光束的传播方向有关,而且与控制光功率有关。最终,获得了高信噪比的EIT谱线。

In order to obtain electromagnetically-induced transparency （EIT） spectra with high signal-to-noise ratio （SNR）, EIT has been investigated based on the cesium （Cs） 6S1/2-6P1/2-8S1/2 ladder-type atomic system. When the probe laser which couples the Cs 6S1/2-6P1/2 transition is frequency locked to hyperfine transition and the controlling laser scans over the Cs 6P1/2-8S1/2 hyperfine transition, the narrow EIT spectra with a flat background is observed, and the spectral SNR is improved. The signal intensity of EIT hyperfine structures depends on not only the alignment of controlling and probe beam, but also the intensity of the controlling laser in ladder-type system. Finally, the EIT spectra with high SNR is obtained.