Light shift compensation in a Rb gas cell frequency standard with two-laser pumping

One of the most important physical processes occurring in Rb frequency standards is the light shift, which depends strongly on the intensity and the optical frequency detuning of the pumping light. This paper presents a method to compensate the light shift by means of two-laser pumping. The two-laser pumping schemes will also improve the signal-to-noise ratio, because almost all atoms can be pumped to the desired state.