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arXiv · 0711.4926

Absolute frequency measurement of the magnesium intercombination transition $^1S_0 \to ^3P_1$

Jan Friebe·André Pape·Matthias Riedmann·Karsten Moldenhauer·Tanja Mehlstäubler·Nils Rehbein·Christian Lisdat·Ernst M. Rasel·Wolfgang Ertmer·Harald Schnatz·Burghard Lipphardt·Gesine Grosche
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Abstract

We report on a frequency measurement of the $(3s^2)^1S_0\to(3s3p)^3P_1$ clock transition of $^{24}$Mg on a thermal atomic beam. The intercombination transition has been referenced to a portable primary Cs frequency standard with the help of a femtosecond fiber laser frequency comb. The achieved uncertainty is $2.5\times10^{-12}$ which corresponds to an increase in accuracy of six orders of magnitude compared to previous results. The measured frequency value permits the calculation of several other optical transitions from $^1S_0$ to the $^3P_J$-level system for $^{24}$Mg, $^{25}$Mg and $^{26}$Mg. We describe in detail the components of our optical frequency standard like the stabilized spectroscopy laser, the atomic beam apparatus used for Ramsey-Bordé interferometry and the frequency comb generator and discuss the uncertainty contributions to our measurement including the first and second order Doppler effect. An upper limit of $3\times10^{-13}$ in one second for the short term instability of our optical frequency standard was determined by comparison with a GPS disciplined quartz oscillator.

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Jan Friebe, André Pape, Matthias Riedmann, Karsten Moldenhauer, Tanja Mehlstäubler, Nils Rehbein, Christian Lisdat, Ernst M. Rasel, Wolfgang Ertmer, Harald Schnatz, Burghard Lipphardt, Gesine Grosche. 2007-11-30. Absolute frequency measurement of the magnesium intercombination transition $^1S_0 \to ^3P_1$. https://doi.org/10.1103/physreva.78.033830

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