Miniaturized timing sources are required in view of various applications in telecommunication, such as e.g. secure inter-satellite telecommunication. In this project, conducted in collaboration with the industrial partner and project leader Temex Neuchâtel Time SA, a strongly miniaturized atomic clock based on a miniature rubidium vapor cell was developed, that demonstrated the required fractional frequency stability of ≤ 10^-11 over few hours to one day., the fully optical laser-based interrogation scheme of Coherent Population Trapping was implemented. In view of still much more radically miniaturized atomic clocks, dedicated miniature rubidium vapor cells were fabricated by silicon microfabrication, and a custom-made integrated circuit serving as microwave frequency synthesizer was developed. These developments pave the way towards Swiss-made chip-scale atomic clocks of only few cubic cm volume and with extremely low power consumption in the few 10 mW to 100 mW range.

This project was conducted in collaboration with Temex Neuchâtel SA (now Spectratime SA) and the Institute of Microtechnology (IMT) of University of Neuchâtel, notably the groups SAMLAB (prof. N. de Rooij) and ESPLAB (prof. P.-A. Farine).