Normal-mode spectroscopy of a single bound atom-cavity system
  The energy-level structure of a single atom strongly coupled to the mode of a high-finesse optical cavity is investigated. The atom is stored in an intracavity dipole trap and cavity cooling is used to compensate for inevitable heating. Two well-resolved normal modes are observed both in the cavity transmission and the trap lifetime. The experiment is in good agreement with a Monte Carlo simulation, demonstrating our ability to localize the atom to within $\lambda/10$ at a cavity antinode. 
P. Maunz, T. Puppe, I. Schuster, N. Syassen, P.W.H. Pinkse, and G.   Rempe