High precision measurement of the hyperfine splitting and ac Stark shift of the $7d$ ${}^2{D}_{3/2}$ state in atomic cesium

Abstract

We report the measurement of hyperfine splitting in the $7d$ ${}^2{D}_{3/2}$ state of ${}^{133}$Cs using high resolution Doppler-free two-photon spectroscopy in a Cs vapor cell. We determine the hyperfine coupling constants $A=7.3509(9)$ MHz and $B=-0.041(8)$ MHz, which represent an order of magnitude improvement in the precision. We also obtain bounds on the magnitude of the nuclear magnetic octupole coupling constant $C$. Additionally, we measure the ac Stark shift of the $6s$ ${}^2{S}_{1/2}\to 7d$ ${}^2{D}_{3/2}$ transition at 767.8 nm to be $-49\pm 5$ Hz/(W/cm${}^2$), in agreement with theoretical calculations. We further report the measurement of collisional shift [$-32.6\pm 2.0$ kHz/mTorr] and pressure broadening for the individual hyperfine levels of the $6s$ ${}^2{S}_{1/2}\to 7d$ ${}^2{D}_{3/2}$ transition. These measurements provide valuable inputs for analysis of systematic effects in optical frequency standards based on the cesium $6s$ ${}^2{S}_{1/2}\to 7d$ ${}^2{D}_{3/2}$ two-photon transition

14 pages, 7 figures, to appear in Physical Review A