Laser spectroscopy and cooling of Yb+ ions on a deep-UV transition
  We perform laser spectroscopy of Yb+ ions on the 4f14 6s 2S_{1/2} - 4f13 5d 6s 3D[3/2]_{1/2} transition at 297 nm. The frequency measurements for 170Yb+, 172Yb+, 174Yb+, and 176Yb+ reveal the specific mass shift as well as the field shifts. In addition, we demonstrate laser cooling of Yb+ ions using this transition and show that light at 297 nm can be used as the second step in the photoionization of neutral Yb atoms. 
Hendrik M. Meyer, Matthias Steiner, Lothar Ratschbacher, Christoph   Zipkes, Michael K\"ohl
physics.atom-ph quant-ph