Quantum control of atomic systems by time-resolved homodyne detection of   spontaneous emission
  We describe the light-matter interaction of a single two level atom with the electromagnetic vacuum in terms of field and dipole variables by considering homodyne detection of the emitted fields. Spontaneous emission is then observed as a continuous fluctuating force acting on the atomic dipole. The effect of this force may be compensated and even reversed by feedback. 
Holger F. Hofmann, Ortwin Hess and Guenter Mahler