Effects of SPM, XPM, and four-wave-mixing in L-band EDFAs on fiber-optic signal transmission

The significance of self-phase modulation (SPM) and cross-phase modulation (XPM) in L-band EDFAs are evaluated through numerical simulations of 20 Gb/s NZDSF transmission links. The results show that SPM and XPM in L-band EDFAs have negligible impairment, compared to that of SPM/XPM effects in NZDSF. An analytical theory describing FWM in an optically amplified multispan fiber line is developed with the inclusion of FWM in EDFAs. The theory predicts that the strength of FWM in L-band EDFAs with small dispersion and high output power can be comparable to that in NZDSF transmission links.