Castagna Natascia, Boudot Rodolphe, Guérandel Stéphane, De Clercq Emeric, Dimarcq Noel, Clairon André
Systèmes de Référence Temps-Espace (SYRTE), Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8630, Paris, France.
IEEE Trans Ultrason Ferroelectr Freq Control. 2009 Feb;56(2):246-53. doi: 10.1109/TUFFC.2009.1033.
We investigated the influence of some critical parameters and operating conditions such as cell temperature, laser intensity, and interrogation technique affecting the performances of a gas cell Cs frequency standard based on coherent population trapping (CPT). Thanks to an original experimental setup, the atoms can be trapped in the dark state and interrogated using continuous wave (CW) or pulsed coherent optical radiations. Using a double-lambda scheme, a signal contrast as high as 52% has been measured in the continuous regime for an optimum cell temperature of 35 degrees C. Compared with the conventional continuous CPT interrogation, the pulsed interrogation technique reduces the light shift by a factor of 300 and allowed it to reach high-frequency stability for higher laser intensities. The frequency stability has been measured to be 9 x 10(-13) for a 1 s integration time. Main noise contributions limiting the short-term and medium-term frequency stability are reviewed and estimated.
我们研究了一些关键参数和操作条件的影响，如池温度、激光强度以及询问技术，这些因素会影响基于相干布居囚禁（CPT）的气室铯频率标准的性能。借助一种原创的实验装置，原子能够被囚禁在暗态，并使用连续波（CW）或脉冲相干光辐射进行询问。采用双λ方案，在连续模式下，对于35摄氏度的最佳池温度，已测得高达52%的信号对比度。与传统的连续CPT询问相比，脉冲询问技术将光频移降低了300倍，并使其在更高激光强度下能够实现高频稳定性。对于1秒的积分时间，频率稳定性已测得为9×10⁻¹³。对限制短期和中期频率稳定性的主要噪声贡献进行了综述和估计。
