Adaptive time-delay hyperchaos synchronization in laser diodes subject   to optical feedback(s)
  In this paper a proposal is made of an adaptive coupling function for achieving synchronization between two lasers subject to optical feedback. Such a control scheme requires knowledge of the systems' parameters. For the first time we demonstrate that when these parameters are not available on-line parameter estimation can be applied.Generalisation of the approach to the multi-feedback systems is also presented. 
E.M.Shahverdiev, R.A.Nuriev, R.H.Hashimov, K.A.Shore