Stimulated Raman Clock Transition Without a Differential ac Stark Shift

Philip Hemmer, M. S. Shahriar, V. D. Natoli +1 more

We have measured the ac Stark effect in a two-zone stimulated Raman interaction in a sodium atomic beam. In addition, we have derived simple theoretical expressions for the ac Stark shift, based on a closed three-level system, in the Λ configuration, and have achieved qualitative agreement with the data. In particular, the magnitude and sense of the ac Stark shifts are found to depend on laser intensities as well as on the initial populations of the two low-lying levels of the Λ configuration. Specifically, the observed ac Stark shifts are smaller for larger laser intensities and also for smaller initial population differences between the two low-lying levels. The ac Stark effect must be considered for many potential applications of the Raman effect, such as a Raman clock. In this connection, we have identified conditions for the reduction of the ac Stark shift in our sodium Raman clock.

Suman S. Dhayal, Yuri V. Rostovtsev

Jon P. Davis, Frank A. Narducci

In this paper, we explore and quantify the effects of stray light on stimulated Raman transitions. The stray light causes decoherence in the measurement of Rabi cycling and also causes increased differential AC Stark shift. These results are quantified as a function of the power of the stray light.

Georges G. Bret, François Gires, Guy Mayer

Rayssa Bruzaca de Andrade, Tobias Gehring, Ulrik L. Andersen

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.