How to reduce FWM impact?

One method to reduce FWM effects is to use transmission fiber that has high chromatic dispersion coefficient at the signal wavelength such as standard single-mode fiber SSMF (ITU-T G.652). The typical chromatic dispersion coefficient of SSMF is 18 ps/nm ⋅ km @ 1550 nm which helps to significantly reduce FWM from occurring. Even a lower chromatic dispersion coefficient significantly helps in reducing FWM such as NZ-DSF fiber (ITU-T G.655). This fiber is specially designed with low chromatic dispersion coefficient (~4 ps/nm ⋅ km @ 1550 nm) for extended transmission distance but high enough to significantly reduce FWM effects.