High stability perspective with pulsed optically pumped frequency standard

The use of pulsed coherent technique in optically pumped vapor cell frequency standards was proposed in sixties by Arditi and Carver in order to eliminate light shift and to increase the stability performances. In this paper, we reconsider the pulsed-scheme idea taking into account the present technology: semiconductor lasers and fast pulsed electronics are nowadays available. We prove here that the microwave detection allows to achieve an atomic quality factor that is twice that obtained with the usual optical detection approach. Moreover, light shift and cavity pulling effects are studied both from the theoretical and the experimental point of view. A very promising preliminary measurement of the frequency stability of our prototype is also reported.