Resonant interaction of optical pulses with plasmonic oscillations in   metal nanoparticles
  We derive envelope equations which generate the Maxwell-Lorentz model and describe the interaction of optical pulses with plasmonic oscillations in metal nanoparticle composites. A family of solitary wave solutions is found which is analogous to self-induced transparency in Maxwell-Bloch. The evolution of incident optical pulses is studied numerically as are the collision dynamics of the solitary waves. These simulations reveal that the collision dynamics vary from near perfectly elastic to highly radiative depending on the relative phase of the initial pulses. 
Ildar R. Gabitov, Robert Indik, Natalia M. Litchinitser, Andrei I.   Maimistov, Vladimir M. Shalaev, Joshua E. Soneson