Light shift reduction in atomic clocks

In this paper we present a detailed description of a method for reduction of the light shift in laser-pumped gas-cell atomic clocks. The method consists in using a multi-frequency optical pumping obtained through frequency modulation of the laser spectrum with precisely controllable parameters. Experimental evidence of a strong reduction of the frequency dependence of the LS in an optical pumping Rb gas-cell clock is demonstrated in a large frequency interval, which is in a very good agreement with the numerical estimations reported.