Compact and high-performance Rb clock based on pulsed optical pumping for industrial application

We report on the development of a compact laserpumped Rb clock based on the pulsed optical pumping (POP) technique, in view of future industrial applications. The clock Physics Package (PP) is based on a compact magnetron-type microwave cavity of 45 cm³ volume, and our current clock PP has a volume of only 0.8 liters, including temperature control and magnetic shields. This clock PP is completed by a newlydeveloped frequency-stabilized laser head of 2.5 liters overall volume, with an acoustic optical modulator (AOM) integrated within the laser head for switching the laser output power. Due to the highly uniform magnetic field inside the microwave cavity, Ramsey signals with high contrast of up to 35% and with a linewidth of 160 Hz have been demonstrated. A typical shortterm clock stability of 2.4×10^-13τ^-1/2 is measured. Thanks to the pulsed operation, the light-shift effect has been considerably suppressed as compared to previously demonstrated continuous-wave (CW) clock operation using the same clock PP, which is expected to enable improved long-term clock stabilities down to the 10^-14 level or better.