Two-frequency Pumping in 87Rb Atomic Beam Frequency Standard with Laser Pumping/Detection for Space Application

We present our study on a two-frequency laser pumped ⁸⁷Rb atomic beam frequency standard for space applications. Two-frequency pumping was studied experimentally with using D2-line for the most efficient scheme (2-2´ sigma; 1-1´ pi) and proposed by us (2-2´ sigma; 1-0´ sigma) scheme. The achieved efficiency for two-frequency pumping using a new scheme was equal to 95%. In the shot noise limit we could achieve instability of sigma_y(tau) les 1ldr10^-13 ldr tau^-1/2 Rb atomic beam frequency standard.