CONSERVED ENERGY APPROXIMATION TO WAVE SCATTERING BY A NONLINEAR INTERFACE

An alternative approach to the investigation of the space-time evoluti on of an electromagnetic field in a nonlinear medium is presented. An adiabatic theory to obtain the dynamic picture of reflection and penet ration of electromagnetic radiation into a nonlinear medium is devised . It is based upon the energy balance equation and uses the nonlinear modes of the stationary problem like trial functions. Filamentation an d soliton generation are analyzed and the model easily predicts the gi ant nonlinear Goos-Hanchen beam shifts that emerge from previously num erically intensive investigations. The method is nonperturbative and i s straightforward to apply to linear-nonlinear interfaces.