A subminiature adjustable and measurable atomic clock based on coherent population trapping

Based on the operating principle and the comprehensive analysis of the coherent population trapping (CPT) atomic clock system, the paper presents an appropriate physics package and design a small and digital servo circuit system, forming a subminiature adjustable and measurable CPT atomic clock system which uses vertical-cavity surface-emitting laser (VCSEL) as optical source, selects ⁸⁵Rb as operating atoms, and is in resonance with the D₁ transitions. The system can be used for experimental study of correlation of each parameter and study of the Ramsey-CPT atomic clock. The whole system, which adequately combines the advantages of the ordinary desktop CPT experimental system and the chip-scale atomic clock (CSAC), is compact, small, low-power and well-adapted, in line with the further requirements of commercial development.