Accurate measurement of the frequency of the 6S–8S two-photon transitions in cesium

Accurate optical frequency measurement is realized on the hyperfine components of the 6S–8S two-photon transition in cesium with an uncertainty of 3×10−10. Light shift and pressure shift are studied. These measurements show that these transitions can be used for the realization of an optical standard at 822 nm, in order to provide new optical frequency references in the visible range.