Optical preparation and measurement of atomic coherence at gigahertz   bandwidth
  We detail a method for the preparation of atomic coherence in a high density atomic medium, utilising a coherent preparation scheme of gigahertz bandwidth pulses. A numerical simulation of the preparation scheme is developed, and its efficiency in preparing coherent states is found to be close to unity at the entrance to the medium. The coherence is then measured non-invasively with a probe field. 
Paul Siddons, Charles S. Adams, and Ifan G. Hughes
physics.atom-ph