Cavity-induced back-action in Purcell-enhanced photoemission of a single   ion in an ultraviolet fiber-cavity
  We study the behavior of a single laser-driven trapped ion inside a microscopic optical Fabry-Perot cavity. In particular, we demonstrate a fiber Fabry-Perot cavity operating on the principal $S_{1/2}\to P_{1/2}$ electric dipole transition of an Yb$^+$ ion at $369\,$nm with an atom-ion coupling strength of $g=2\pi\times 67(1)\,$MHz. We employ the cavity to study the generation of single photons and observe cavity-induced back-action in the Purcell-enhanced emission of photons. Tuning of the amplitude and phase of the back-action allows us to enhance or suppress the total rate of photoemission from the ion-cavity system. 
T. G. Ballance, H. M. Meyer, P. Kobel, K. Ott, J. Reichel and M.   K\"ohl
quant-ph