The MAC - a miniature atomic clock

The authors are developing a chip-scale atomic clock (CSAC), more than two orders of magnitude smaller and lower power than any existing technology. As an intermediate milestone, en route to the ultimate CSAC objectives, we have developed a miniature atomic clock (MAC), combining the low-power CSAC physics package with a low-parts count, low-power digital control and microwave system. The MAC is a complete packaged atomic clock, with overall size of 10 cm³, power consumption >200 mW, and short-term stability σ_y(τ)∼4×10^-10τ^{- 1}2 /. The MAC provides a valuable testbed for the further development and refinement of the CSAC physics package as well as for the development of the CSAC control electronics prior to undertaking the costly and time-consuming size-reduction effort which will be necessary to meet the ultimate CSAC objectives. The MAC itself may find applications in commercial and military timing systems which require the relatively small size and power consumption of the MAC now, rather than wait for the evolution of the 1 cm³, 30 mW CSAC.