Review of chip-scale atomic clocks based on coherent population trapping

Jaques Vanier

Zhong Wang

Research on chip-scale atomic clocks (CSACs) based on coherent population trapping (CPT) is reviewed. The background and the inspiration for the research are described, including the important schemes proposed to improve the CPT signal quality, the selection of atoms and buffer gases, and the development of micro-cell fabrication. With regard to the reliability, stability, and service life of the CSACs, the research regarding the sensitivity of the CPT resonance to temperature and laser power changes is also reviewed, as well as the CPT resonance's collision and light of frequency shifts. The first generation CSACs have already been developed but its characters are still far from our expectations. Our conclusion is that miniaturization and power reduction are the most important aspects calling for further research.

Yi Yin, Yi Zhang, Tan Bo-Zhong +2 more

To Obtain an appropriate coherent population trapping (CPT) signal through a miniature atomic vapor cell is one of the key steps to implement a chip-scale atomic clock (CSAC). In the present experiment, the high S/N differential CPT spectral line has been achieved with a miniature atomic vapor cell through modulating the laser and extracting 87Rb atom laser interacting signal using the phase sensitive demodulation technique. With the spectral line, the dependence of CPT signal on the working parameters and the dependence of frequency stability of CSAC on the quality of the CPT signal have been studied; the obtained experimental results agree well with the theoretical prediction, which can be used as the recommended working parameters for CSAC. The methods exploited in the experiment can be implemented in the resource of a CSAC, therefore this experiment explores for CSAC the practical approaches of performance optimization.

Stéphane Guérandel, Jean-Marie Danet, Peter Yun +1 more

Vishal Shah

Lin Yang

This paper introduces the chip-scale atomic clock(CSAC) based on coherent population trap(CPT) theory. CPT clock is the representative of atomic miniature atomic clock in the future. Standing progress has been made for CPT clock in designing techniques, manufacturing technology, and physics mechanism,in recent years. Principle prototype of the CSAC has been developed. According to the developing trend, product of the CSAC will be offered to customer in three or five years.