Cold-Atom-Based Commercial Microwave Clock at the 10−15 Level

Laser cooled atomic clocks allow to both extend spectroscopy duration and better control the systematics. We present a commercial microwave clock that achieve an extreme stability of 3.2×10
^-13
at 1 s and 1×10
^-15
in less than 2 days, with a turnkey product dedicated for continuous long-term operation.