Observation of sub-Poisson photon statistics in the cavity-QED   microlaser
  We have measured the second-order correlation function of the cavity-QED microlaser output and observed a transition from photon bunching to antibunching with increasing average number of intracavity atoms. The observed correlation times and the transition from super- to sub-Poisson photon statistics can be well described by gain-loss feedback or enhanced/reduced restoring action against fluctuations in photon number in the context of a quantum microlaser theory and a photon rate equation picture. However, the theory predicts a degree of antibunching several times larger than that observed, which may indicate the inadequacy of its treatment of atomic velocity distributions. 
Wonshik Choi, Jai-Hyung Lee, and Kyungwon An (Seoul National   University), C. Fang-Yen, R. R. Dasari, and M. S. Feld (Massa...