A collective modulation instability of multiple four-wave mixing
  We investigate the modulation instability of multiple four-wave mixing arising from a dual-frequency pump in a single-mode fiber or waveguide. By applying the Floquet theory on account of the periodic nature of four-wave mixing, we reveal a collective type of instability occurring in the anomalous dispersion regime. Our interpretation of the linear stability analysis is validated by the numerical solution of the nonlinear Schroedinger equation 
Andrea Armaroli and Stefano Trillo
physics.optics nlin.PS