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Q: Fachverband Quantenoptik und Photonik
Q 21: Ultracold Atoms and Plasmas (joint session Q/A)
Q 21.3: Poster
Tuesday, March 15, 2022, 16:30–18:30, P
Improved Laser System for Optical Trapping of Neutral Mercury — •Rudolf Homm, Tatjana Beynsberger, and Thomas Walther — Technische Universität Darmstadt, Institut für Angewandte Physik, Laser und Quantenoptik, Schlossgartenstraße 7, 64289 Darmstadt
Cold Hg-atoms in a magneto-optical trap offer opportunities for various experiments. The two stable fermionic isotopes are interesting with regard to a new time standard based on an optical lattice clock employing the 1S0 - 3P0 transition at 265.6 nm. The five stable bosonic isotopes can be used to form ultra cold Hg-dimers through photo-association in connection with vibrational cooling by applying a specific excitation scheme.
The laser system consists of an MOFA-Setup at 1014.8 nm followed by two consecutive frequency-doubling stages. Due to a new high-power diode and a 50 W-pump laser at 976 nm the fundamental power was amplified up to 12 W. This results in up to 5 W at 507.4 nm after the first frequency-doubling cavity.
The limiting factor in generating high power at 253.7 nm so far, was the degradation of the non-linear BBO-crystal used in the second frequency-doubling stage. To avoid this problem, we developed and tested a cavity with elliptical focusing [1,2]. This new cavity produces over 700 mW at 253.7 nm without a sign of degradation. We will report on the status of the experiments.
[1] Preißler, D., et al., Applied Physics B 125 (2019): 220
[2] Kiefer, D., et al., Laser Physics Letters 16 (2019): 075403