Absolute frequency measurements on the $5s5p^{3}$P$_{0}\to5s6d^{3}$D$_{1}$ transition in strontium

Abstract: We report the first absolute frequency measurements for the $5s5p^{3}$P${0}\to5s6d^{3}$D${1}$ transition at 394 nm for all the stable strontium isotopes by utilizing repumping induced spectroscopy in a magneto-optical trap. Absolute transition frequency is measured to be 760524409251(25) kHz for $^{88}$Sr.With reference to $^{88}$Sr, the isotope shifts are measured to be 91052(35), 54600(33), and 51641(28) kHz for $^{84}$Sr, $^{86}$Sr, and $^{87}$Sr, respectively. We calculate the hyperfine constants A and B for the fermionic isotope $^{87}$Sr at kHz level. Furthermore, we perform King plot analysis by combining isotope shifts on the 689-nm transition to our data.