Investigation on light shift in CPT-Ramsey resonance for compact atomic clocks

This paper presents a theoretical and experimental investigation on the light shift (AC Stark shift) of the 6²S_1/2 (F = 3 ↔ 4) transition in ¹³³Cs, as observed through coherent population trapping (CPT) under a pulsed excitation. The calculated results are good agreement in the experimental results on various parameters and show that the light shift under pulsed excitation is 20~30 times less than that under continuous excitation. In addition, this paper also presents a two-step pulse method for suppressing the light shift.