Stuttgart 2012 – wissenschaftliches Programm
Q 34.43: Poster
Dienstag, 13. März 2012, 16:30–19:00, Poster.I+II
Optical trapping of neutral mercury — •Holger John, Patrick Villwock, and Thomas Walther — Technische Universität Darmstadt, Institut für Angewandte Physik, Laser- und Quantenoptik, Schlossgartenstraße 7, 64289 Darmstadt
Laser-cooled mercury constitutes an interesting starting point for various experiment inparticular in light of the existence of bosonic and fermionic isotopes in relatively high natural abundance. On the one hand the fermionic isotopes could be used to develop a new time-standard based on a lattice optical clock employing the 1 S0 - 3 P0 transition at 265,6 nm. Another interesting venue is the formation of ultra cold Hg-dimers employing photo-association and achieving vibrational cooling by employing a special scheme.
A Yb:disc laser at 1014.8 nm is used for the trapping laser which is frequency-doubled twice to deliver up to 280 mW at 253.7 nm for the repump-free cooling process. For the photo-association process a fiber amplified and frequency quadrupled ECDL at 1016.4 nm is being setup which results in a large tuning range in the UV.
Due to the required power in the UV a power of about 5 W is needed in the fundamental. Since a linewidth of less than 1,27 MHz given by the cooling transition some care must be taken. We have successfully trapped the bosonic 202Hg as well as the fermionic 199Hg isotopes and have performed first temperature measurement. Currently, we are focussing on improving the reliability of the cooling and also of the photo-association-spectroscopy laser system. We will report on the status of the experiments.