Compact atom-based clocks

Over the past couple of decades, cold atom clocks that provide frequency standards mainly come from atomic fountain clocks which are found only in national research laboratories. However, there is increasing demand for higher accuracy compact clock systems for use in remote and mobile situations. These compact clocks have applications in 5G synchronisation, GNSS (Global Navigation Satellite Systems) holdover, and tests of fundamental physics. Existing portable thermal atom-based clocks are becoming limited in their capabilities for the most advanced measurement science/physics and engineering applications. Consequently, there is a need for compact cold atom clocks with novel engineering and physics adaptations which can provide improved accuracy/performance.

The primary objective of this research is to investigate and develop novel cold atom clocks and engineering science, that will allow the development of prototype compact clock systems that offer improved accuracy/performance over existing compact clock technologies
Exploring cold-atom clock approaches in a compact form factor will involve:
1. Using light-based atom guiding techniques to confine atoms away from vacuum vessel walls, thus reducing atom wall collisions
2. Reducing the atom temperatures to sub milli-kelvin levels thereby enabling optical molasses using laser cooling techniques
3. Investigating combinations of different atom trapping techniques such as magneto optical traps and optical lattice traps with quantum state preparation methods
4. Investigating various clock interrogation schemes to extract a frequency/timing reference. (coherent population trapping, double resonance, two photon absorption, pulsed optical pumping)
5. Designing and engineering a reliable portable miniature apparatus with optoelectronic servo control algorithms

The novelty of the project will lie in combining the different approaches described above in a miniature form factor whilst producing a superior clock performance compared to existing portable clock systems. This research is being carried out at the National Physical Laboratory where there is a wide range of expertise in the field of atomic timekeeping. The research conducted here is anticipated to serve the follow-on generation of compact atomic clocks.