Complex dynamics and configurational entropy of spatial optical solitons   in nonlocal media
  Intense light propagating in a nonlinear medium can generate an ensemble of interacting filaments of light, or spatial solitons. Using nematic liquid crystals, we demonstrate that they undergo a collective behavior typical of complex systems, including the formation of clusters and sound-like vibrations, as well as the reduction of the configurational entropy, controlled by the degree of nonlocality of the medium. 
Claudio Conti, Marco Peccianti, Gaetano Assanto