Microfabricated cells for chip-scale atomic clock based on coherent population trapping: fabrication and investigation
The article is devoted to investigation of the coherent population trapping (CPT) signals in the microfabricated alkali metal vapor cell. At the first step the experimental technological setup for MEMS manufacture was assembled. The microfabricated cell was designed to realize two optical pumping schemes: the conventional one where the cell is just placed under the laser beam, and another one with double reflection of the laser beam to increase the beam path in narrow cell space). The inflation of the cell with alkali metal (87Rb), buffer gas type and gas pressure were calculated preliminary. The miniature cells with alkali metal were manufactured using laser activation. To measure the CPT signals the experimental setup was used, and characteristics of CPT resonance signals were obtained. The resonance line width of 2 – 3 kHz and signal-to-noise ratio of 1500 in 1 Hz band width were found. These parameters of the CPT resonance line can provide the frequency non-stability of the small-scale atomic clock at the level of 10–11 for 100 s of measuring time. The results obtained suggested several leads for future research.