If you intend to show the effect of dispersion, you’d better use sweep iteration for several dispersion values to see how it influences FWM. This you can easily do without any former knowledge of what values make what changes. But you can have a look at papers in this regard by googling them. I suggest having a look at IEEE paper “Effect of Chromatic Dispersion on Four-Wave Mixing in Optical WDM Transmission System” which I found closer to your purpose among the papers I found by google search.
Cheers!