Compact clocks for industrial applications: The EMRP project IND 55 MClocks

Vapor cell atomic clocks are an interesting technology because they combine compactness, low power consumption and excellent relative frequency stability. Recently, due to better performing laser sources and innovative techniques to prepare and detect the atoms, several cell-based prototypes exhibiting unprecedented frequency stability have been developed. These techniques allow a reduction in the transfer of laser noise to the atoms, improvement of the signal-to-noise ratio and subsequently the clock's frequency stability. The project IND55 Mclocks funded by the European Metrological Research Programme (EMRP) proposes to develop high performances vapor cell clocks for industrial applications. Three technologies are investigated: 1) the pulsed optical pumping (POP) scheme; 2) the cold atoms approach, and 3) the Coherent Population Trapping (CPT). The results related to the first period of activity are presented.