Quantitative analysis of optical surge propagation on transmission systems

Since WDM technology became the most promising scheme to enhance transmission capacity, the optical surge in amplifier repeater systems has become an important issue. Indeed, since WDM transmission systems require Er³⁺-doped fiber amplifiers (EDFAs) with a large gain, the optical surge might grow large enough to damage optical components in the system. We have numerically analyzed the propagation of optical surges in transmission systems and estimated the surge peak quantitatively. We have also confirmed the validity of the simulation technique by comparing the simulated and experimental results. Propagation characteristics of optical surges in amplified transmission systems have been evaluated. It has been found that the maximum value of the optical surge can be suppressed by regulating the switching time constants of input signal