Photon lifetime in a cavity containing a slow-light medium
  We investigate experimentally the lifetime of the photons in a cavity containing a medium exhibiting strong positive dispersion. This intracavity positive dispersion is provided by a metastable helium gas at room temperature in the electromagnetically induced transparency (EIT) regime, in which light propagates at a group velocity of the order of 10000 m/s. The results definitely prove that the lifetime of the cavity photons is governed by the group velocity of light in the cavity, and not its phase velocity. 
Thomas Laupr\^etre (LAC), C\'edric Proux (LAC), Rupamanjari Ghosh   (JNU), Sylvain Schwartz (TRT), Fabienne Goldfarb (LAC), ...
physics.optics quant-ph