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arXiv · 1906.08798

Buffer-gas cooling, high-resolution spectroscopy and optical cycling of barium monofluoride molecules

Ralf Albrecht·Michael Scharwaechter·Tobias Sixt·Lucas Hofer·Tim Langen
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Abstract

We demonstrate buffer-gas cooling, high-resolution spectroscopy and cycling fluorescence of cold barium monofluoride (BaF) molecules. Our source produces an intense and internally cold molecular beam containing the different BaF isotopologues with a mean forward velocity of 190 m/s. For a well-collimated beam of 138BaF we observe a flux of more than 1e10 molecules/sr/pulse in the X2Sigma, N=1 state in our downstream detection region. Studying the absorption line strength of the intermediate A'Delta state we infer a lifetime of 790+\-346 ns, significantly longer than previously estimated. Finally, highly-diagonal Franck-Condon factors and magnetic remixing of dark states allow us to realize a quasi-cycling transition in 138BaF that is suitable for future laser cooling of this heavy diatomic molecule.

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Ralf Albrecht, Michael Scharwaechter, Tobias Sixt, Lucas Hofer, Tim Langen. 2020-01-10. Buffer-gas cooling, high-resolution spectroscopy and optical cycling of barium monofluoride molecules. https://doi.org/10.1103/physreva.101.013413

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