Development of a single-frequency optically-pumped cesium beam resonator for space applications

Observatoire de Neuchâtel (ON) is developing a compact optically-pumped cesium beam frequency standard in the frame of an ESA-ARTES 5 project. The simplest optical scheme, which is based on a single optical frequency for both preparation and detection processes of atoms, has been chosen to fulfill reliability constraints of space applications. With our laboratory demonstrator, we have measured a frequency stability of σ_y=2.74×10^-12τ^-1/2, which is compliant with the Galileo requirement. Present performance limitations are discussed and further improvements are proposed in order to reach our ultimate frequency stability goal of σ_y=1×10^-12τ^-1/2.