Effective suppression of penalties induced by parametric nonlinear interaction in distributed Raman amplifiers based on NZ-DS fibers

We discuss penalties induced by pump intensity noise transfer and parametric nonlinear interactions in counterpumped distributed Raman amplifiers based on nonzero dispersion shifted fibers. An effective suppression of penalties induced by parametric nonlinear interaction is experimentally demonstrated by a new Raman pump module, based on cascaded fiber Raman lasers.