Comment on "Direct Observation of Optical Precursors in a Region of   Anomalous Dispersion"
  We show that the optical transients recently read as "Sommerfeld-Brillouin precursors" by Jeong, Dawes and Gauthier are not identifiable with optical precursors (unless one considers that any coherent transient propagating in a dilute medium at the velocity c is an optical precursor) and that they can be interpreted in very simple physical terms. 
Bruno Macke (PhLAM), Bernard S\'egard (PhLAM)