Solitons propagation in non-homogeneous periodic media by tandem arrangement of nonlinear materials

In this work we discuss the characteristics of the resonant pulse propagation through a sequence of two level atom media and in the presence of intensity dependent nonlinearities that occur in Kerr & photorefractive materials. The area theorem conveniently describe the evolution of the soliton eigenvalues through the stratified medium, an essential analytical tool lacking in the intensity dependent nonlinearities, thereof its understanding clarifies the general problem. We can conclude that rather than a mean soliton, we have a modulated solution.