Isotope shifts and hyperfine splitting of the ${}^1{S}_0\to {}^3{P}_1$ transition in zinc

Abstract

We report laser-induced-fluorescence spectroscopy of the ${}^1{S}_0\to {}^3{P}_1$ intercombination transition in neutral zinc at $307.6\mathrm{nm}$. Isotope shifts are measured for all stable isotopes with kHz-level precision, improving previous data by about two orders of magnitude. For ${}^{67}\mathrm{Zn}$, we resolve the excited-state hyperfine structure and determine $\delta {\nu }_{\mathrm{COG}}^{67,64}=1085.933(7)\mathrm{MHz}$, $A=608.922(3)\mathrm{MHz}$, and $B=-18.995(10)\mathrm{MHz}$. A King plot comparison with the ${}^1{S}_0\to {}^1{P}_1$ 214-nm transition results in field- and mass-shift parameters of $F_{307.6,214}=1.17(5)$ and $K_{307.6,214}=-153(60)\mathrm{GHz}\mathrm{u}$. These results provide the spectroscopic basis for narrow-line cooling and precision measurements based on zinc, including the development of an optical clock.