Analysis of the Crosstalk in WDM Systems Caused by Cross-phase Modulation in Erbium-doped Fiber Amplifiers

The crosstalk in WDM systems caused by cross phase modulation (XPM) in erbium doped fiber amplifiers(EDFA) was studied analytically. The results confirm that the EDFA induced phase shift does cause crosstalk in WDM systems. The crosstalk between two channels both with modulated pulse signals is studied for the first time. It was found that the EDFA induced phase shift will cause serious deterioration of the eye diagram when the optical signals continue to travel in the normal dispersion regime of the transmission fiber, while in the anomalous dispersion regime this phase shift will not cause much deterioration of the eye diagram.