This paper presents the principle of Coherent Population Trapping(CPT) atomic clock and gives the mathematical process of information extraction and process in the clock.Then one frame of the realization of the circuit system of CPT atomic clock is defined.
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, selects85Rb as operating atoms, and is in resonance with the D1transitions. 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.
Based on the model of the Λ-type three-level atomic system, the principle, the evolutionary equations and the resonance line characteristics of the coherent population trapping (CPT) are analyzed by means of ensemble-averaged density matrix approach. The paper presents a schematic illustration of practical realization and a block scheme of comprehensive analysis of the CPT system. Using vertical-cavity surface-emitting laser (VCSEL) as optical source, we propose an appropriate physics package and design a small and digital servo circuit system, forming a subminiature adjustable and measurable CPT atomic clock system. The whole system is compact, small, low-power and well-adapted, in line with the further requirements of commercial development.