Recent Results on a Rb Pulsed Optically Pumped Clock for Space Applications

We report on the recent characterization of a Rb microwave clock based on the pulsed optical pumping (POP) principle. The clock is developed in the frame of a INRIM-Leonardo collaboration intended to implement a highly stable and compact device for space applications. The physics package developed by Leonardo S.p.A. includes space-graded components, weights less than 4 kg and occupies only a 4-liters volume. It has been characterized with custom optics and electronics developed at INRIM laboratories. By taking advantage of advanced stabilization techniques for the laser and microwave pulses, this arrangement exhibits state-of-the-art short- and mid-term stability, reaching σ y (40000s) = 6×10 −16 (drift removed) for a 200000s run.