Single photon generation by pulsed excitation of a single dipole
  The fluorescence of a single dipole excited by an intense light pulse can lead to the generation of another light pulse containing a single photon. The influence of the duration and energy of the excitation pulse on the number of photons in the fluorescence pulse is studied. The case of a two-level dipole with strongly damped coherences is considered. The presence of a metastable state leading to shelving is also investigated. 
Rosa Brouri, Alexios Beveratos, Jean-Philippe Poizat and Philippe   Grangier