Interrogation oscillator noise rejection in the comparison of atomic fountains.

ABSTRACT

The frequency stability of an atomic fountain clock can be limited by the phase noise of the interrogation oscillator via the "Dick effect." In this paper we demonstrate the rejection of the phase fluctuations of the interrogation oscillator by the synchronization of atomic fountains. A reduction by a factor of 16 in the Allan standard deviation of the relative frequency difference between two fountains has been obtained.