The Optical Stark Shift on a Two-Photon Transition in Rubidium

An atomic clock designed around the 778 nm two-photon transition in rubidium vapor has become an appealing option for future portable optical clocks. However, two-photon transitions are known to suffer from large AC Stark shifts. We present an analysis of the AC Stark shift in the
$5\mathrm{S}_{1/2}\rightarrow 5\mathrm{D}_{5/2}$
two photon transition of Rb, along with an improved determination of the blackbody radiation Stark shift.