Absolute frequency measurement of the In${}^{+}$ clock transition with a mode-locked laser

J. von Zanthier, Th. Becker, M. Eichenseer +11

The absolute frequency of the In${}^{+}$ $5s^{21}{S}_0$ - $5s5p^3{P}_0$ clock transition at 237 nm was measured with an accuracy of 1.8 parts in $10^{13}$. Using a phase-coherent…