Coherent Propagation of Polaritons in Semiconductor Heterostructures:   Nonlinear Pulse Transmission in Theory and Experiment
  The influence of coherent optical nonlinearities on polariton propagation effects is studied within a theory-experiment comparison. A novel approach that combines a microscopic treatment of the boundary problem in a sample of finite thickness with excitonic and biexcitonic nonlinearities is introduced. Light-polarization dependent spectral changes are analyzed for single-pulse transmission and pump-probe excitation. 
S. Schumacher, G. Czycholl, F. Jahnke, I. Kudyk, L. Wischmeier, I.   R\"uckmann, T. Voss, J. Gutowski, A. Gust, and D. Hommel