Hyperfine-structure-constant determination and absolute-frequency measurement of the Rb4D3/2state

Abstract

The frequency of a laser diode is stabilized onto the line centers of double-resonance optical pumping spectra, and the absolute frequencies of the hyperfine-structure components of the $5{P}_{3/2}\text{\ensuremath{-}}4{D}_{3/2}$ excited-state transition for two isotopes of $^{87}\text{R}\text{b}$ and $^{85}\text{R}\text{b}$ atoms are measured using a fiber femtosecond frequency comb system. The $4{D}_{3/2}$ state hyperfine-structure constants of the two Rb isotopes are determined by utilizing the measured absolute optical frequency and the ratio of the hyperfine-structure constants for the two Rb isotopes from the accurately determined values of other states of rubidium. The magnetic-dipole constants $A$ are determined to be 24.75(12) MHz for $^{87}\text{R}\text{b}$ and 7.329(35) MHz for $^{85}\text{R}\text{b}$. The uncertainties of both results are reduced by one order compared to previous results. The electric-quadrupole constants $B$ are determined to be 2.19(11) and 4.52(23) MHz for $^{87}\text{R}\text{b}$ and $^{85}\text{R}\text{b}$, respectively