Eigenvalue Switching by Cascading

Self-action of light is a subject of constant intense investigation due to the fascinating phenomena encountered and their potential applications to all-optical, ultrafast signal processing devices. Optical solitons play a central role in such scenario because of their unique particlelike properties. Until recently optical solitons have been mainly pursued using the optical Kerr effect in cubic nonlinear media, and the photorefractive effect. The propagation of light in cubic nonlinear media is described by the nonlinear Schröedinger (NLSE) which in appropriate waveguide settings has both single and higher-order soliton solutions, and various types of devices based on such solitons have been proposed. Higher-order solitons are bound states of several single solitons. In the framework of the inverse scattering transform the number of solitons of the NLSE contained into an input light signal is given by the number of eigenvalues of the Zakharov-Shabat scattering The bound states contain no binding energy and they can be destroyed by different physical mechanisms that appear as perturbations to the NLSE.