Light shift in modulated coherent population trapping atomic clocks

Abstract

We have studied the light shift in coherent population trapping (CPT) atomic clocks under full band modulation (FBM) and under half band modulation (HBM). The theoretical results show that the light shift under FBM is only 1/4 of the light shift under HBM. Our experimental results confirm the theoretical results. Therefore, we can easily improve the stability of CPT clocks by replacing HBM with FBM.