Multifrequency nonlinear Schrödinger equation

The multifrequency character of nonlinearity dispersion is often dismissed because, in principle, it increases the computational load exceedingly rendering an impractical modeling and, typically, nonlinearities barely depend on frequency. Nonetheless, nonlinearity dispersion has recently enabled a solution to a long-standing challenge in optics. To explore the potential of this research avenue on solid theoretical grounds, we derive a propagation equation accounting for multifrequency nonlinearities rigorously that maintains the computational advantages of conventional models.