Godone Aldo, Micalizio Salvatore, Levi Filippo, Calosso Claudio
Istituto Nazionale di Ricerca Metrologica, INRIM, Strada delle Cacce 91, 10135 Torino, Italy.
Rev Sci Instrum. 2011 Jul;82(7):074703. doi: 10.1063/1.3606641.
In this paper, we report an analysis of the design criteria of microwave cavities for vapor cell frequency standards. Two main geometries exploited in those devices are considered: the cylindrical cavity, used, for example, in the coherent population trapping maser and in the pulsed optically pumped (POP) clock, and the spherical cavity used in the isotropically laser cooled clock. The cavity behavior is described through a lumped equivalent circuit in which the input coupling loop, the dielectric cell containing the atoms and the diodes for frequency tuning or Q control are taken into account. In particular, the effect of the cell on the cavity resonance frequency is analytically evaluated via a first-order perturbation approach. The theory is found in good agreement with the experiments performed with two different cylindrical cavities used for the POP clock; the model here developed can then be helpful in the design of the cavity system. The general principles here reported can be adapted to other standards, such as atomic fountains and hydrogen masers, and to other modes and/or geometries.
在本文中，我们报告了对用于汽室频率标准的微波腔设计标准的分析。考虑了这些装置中采用的两种主要几何结构：例如，用于相干布居囚禁微波激射器和脉冲光泵浦（POP）时钟的圆柱形腔，以及用于各向同性激光冷却时钟的球形腔。通过集总等效电路来描述腔的行为，其中考虑了输入耦合环、包含原子的介质腔以及用于频率调谐或品质因数控制的二极管。特别地，通过一阶微扰方法对腔对腔共振频率的影响进行了分析评估。该理论与使用用于POP时钟的两个不同圆柱形腔进行的实验结果吻合良好；这里开发的模型随后可有助于腔系统的设计。这里报告的一般原理可适用于其他标准，如原子喷泉和氢微波激射器，以及其他模式和/或几何结构。
