Intercombination line frequencies in ${}^{171}$Yb validated with the clock transition

Abstract

We have carried absolute frequency measurements of the $(6s^2){}^1{S}_0$ $-$ $(6s6p){}^3{P}_1$ transition in ${}^{171}$Yb (the intercombination line), where the spin-1/2 isotope yields two hyperfine lines. The measurements rely on sub-Doppler spectroscopy to yield a discriminator to which a 556 nm laser is locked. The frequency reference for the optical frequency measurements is a high-quality quartz oscillator steered to the GNSS timescale that is bridged with a frequency comb. The reference is validated to $\sim 3\times 10^{-12}$ by spectroscopy on the ${}^1{S}_0-{}^3{P}_0$ (clock) line in laser cooled and trapped ${}^{171}$Yb atoms. From the hyperfine separation between the $F=1/2$ and $F=3/2$ levels of ${}^3{P}_1$ we determine the hyperfine constant to be $A{(}^3{P}_1)=3957833(28)$ kHz.

10 pages, 9 figures

References in corpus (6)

• An atomic clock with $1\times 10^{-18}$ room-temperature blackbody Stark uncertainty
• Improved frequency measurement of a one-dimensional optical lattice clock with a spin-polarized fermionic ${}^{87}$Sr isotope
• Doppler-free spectroscopy of the 1S0-3P0 optical clock transition in laser-cooled fermionic isotopes of neutral mercury
• Determination of the 5d6s 3D1 state lifetime and blackbody radiation clock shift in Yb
• Absolute frequency measurement of the 1S0 - 3P0 transition of 171Yb
• Absolute frequency measurement with uncertainty below $1\times 10^{-15}$ using International Atomic Time