Double-modulation CPT cesium compact clock

8th Symposium on Frequency Standards and Metrology 2015

Yun, Peter^1 ; Mejri, Sinda^1 ; Tricot, Francois^1 ; Hafiz, Moustafa Abdel^2 ; Boudot, Rodolphe^2 ; De Clercq, Emeric^1 ; Guérandel, Stéphane^1

LNE-SYRTE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, 61 avenue de l'Observatoire, Paris

75014, France^1

FEMTO-ST, CNRS, UFC, 26 chemin de l'épitaphe, Besançon Cedex

25030, France^2

关键词: Atomic population;    Clock transition;    Coherent population trapping;    Double modulation;    Laser polarization;    Optimal parameter;    Optimal polarization;    Synchronous modulation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/723/1/012012/pdf
DOI  :  10.1088/1742-6596/723/1/012012

来源: IOP

【 摘 要 】

Double-modulation coherent population trapping (CPT) is based on a synchronous modulation of Raman phase and laser polarization, which allows the atomic population to accumulate in a common dark state. The high contrast signal obtained on the clock transition with a relative compact and robust laser system is interesting as basis of a high performance microwave clock. Here we study the parameters of a double-modulation CPT Cs clock working in cw mode. The optimal polarization modulation frequency and cell temperature for maximum contrast of clock transition are investigated. The parameters of the detection are also studied. With the optimal parameters, we observe a CPT signal with contrast of 10% and linewidth of 492 Hz, which is well suited for implementing a cw atomic clock.