title: Improvement of the frequency stability below the Dick limit with a continuous atomic fountain clock.
abstract: The frequency instability of a shot-noise limited atomic fountain clock is inversely proportional to its signal-tonoise ratio. Therefore, increasing the atomic flux is a direct way to improve the stability. Nevertheless, in pulsed operation, the local oscillator noise limits the performance via the Dick effect. We experimentally demonstrate here that a continuous atomic fountain allows one to overcome this limitation. In this work, we take advantage of two-laser optical pumping on a cold cesium beam to increase the useful fountain flux and, thus, to reduce the frequency instability below the Dick limit. A stability of 6 × 10(-14)τ(-1/2) has been measured with the continuous cesium fountain FOCS-2.
authors.forename: Laurent
authors.initials: L
authors.lastname: Devenoges
authors.forename: André
authors.initials: A
authors.lastname: Stefanov
authors.forename: Alain
authors.initials: A
authors.lastname: Joyet
authors.forename: Pierre
authors.initials: P
authors.lastname: Thomann
authors.forename: Gianni
authors.initials: G
authors.lastname: Di Domenico