High-precision measurement of the hyperfine splitting and ac Stark shift of the 7d D3/22 state in atomic cesium

Abstract

We report the measurement of hyperfine splitting in the $7d$ $^{2}D_{3/2}$ state of $^{133}\mathrm{Cs}$ 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 $B=\ensuremath{-}0.041(8)$ 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 $6s\phantom{\rule{0.16em}{0ex}}^{2}\mathrm{S}_{1/2}\ensuremath{\rightarrow}7d$ $^{2}D_{3/2}$ transition at 767.8 nm to be $\ensuremath{-}49\ifmmode\pm\else\textpm\fi{}5\phantom{\rule{0.16em}{0ex}}\mathrm{Hz}/(\mathrm{W}/\mathrm{c}{\mathrm{m}}^{2})$, in agreement with theoretical calculations. We further report the measurement of collisional shift (\ensuremath{-}32.6 \ifmmode\pm\else\textpm\fi{} 2.0 kHz/mTorr) and pressure broadening for the individual hyperfine levels of the $6s\phantom{\rule{0.16em}{0ex}}^{2}\mathrm{S}_{1/2}\ensuremath{\rightarrow}7d$ $^{2}D_{3/2}$ transition. These measurements provide valuable inputs for analysis of systematic effects in optical frequency standards based on the cesium $6s\phantom{\rule{0.16em}{0ex}}^{2}\mathrm{S}_{1/2}\ensuremath{\rightarrow}7d$ $^{2}D_{3/2}$ two-photon transition.