Stable isochronal synchronization of mutually coupled chaotic lasers
  The dynamics of two mutually coupled chaotic diode lasers are investigated experimentally and numerically. By adding self feedback to each laser, stable isochronal synchronization is established. This stability, which can be achieved for symmetric operation, is essential for constructing an optical public-channel cryptographic system. The experimental results on diode lasers are well described by rate equations of coupled single mode lasers. 
Einat Klein, Noam Gross, Michael Rosenbluh, Wolfgang Kinzel, Lev   Khaykovich, Ido Kanter