AC Stark shift in Ramsey-CPT resonance under $\Lambda$-type three level atomic system

Wu, Wenguo, Peng +1 more

Monojit Kora, Swapan Mandal

Nikolai B. Delone, В. П. Крайнов

J. W. Pollock, Valeriy I. Yudin, M. Shuker +5 more

The off-resonant ac Stark shift for coherent population trapping (CPT) resonances probed with Ramsey spectroscopy is investigated experimentally and theoretically. Measurements with laser-cooled $^{87}\mathrm{Rb}$ atoms show excellent quantitative agreement with a simple theory. The shift depends on the relative intensity of the two CPT light fields, but depends only weakly on the total intensity. Since the origin of the shift is through couplings of the interrogation light to off-resonant excited-state hyperfine levels, the size and sign of the shift depend on the specific interrogation scheme. The theory also shows that for several commonly used interrogation schemes it is possible to minimize the off-resonant light shift or its dependence on the CPT intensity ratio by properly selecting the system parameters.

Nikolai B. Delone, В. П. Крайнов

Junhai Zhang, Jingbiao Chen

For the two-photon ac Stark effect in Raman-Ramsey configuration, such as the Raman clock, and pulsed CPT clock configuration, an interference phenomenon of two-photon ac Stark effect is predicted. Here we report this new physical phenomenon, the interference of two-photon ac Stark effect in two-zone Raman-Ramsey interactions, which is general in any Raman-Ramsey spectroscopy. In particular, for an atomic beam Raman clock configuration, the ac Stark shift will present an interference fringe caused by the separated oscillatory-field interaction when the shift fields interact with atoms at two zones. On the center of dispersion shape of normal ac-Stark shift, an interference pattern appeared when the scale of frequency detuning is expanded.