Numerical model for the study of the behavior of an erbium amplifier for the evaluation of the transmission performance of optical WDM systems

In this work we present a numerical code for evaluating the system performa nces of wavelength division multiplexed (WDM) point-to-point optically ampl ified links, taking into account the behavior of the erbium amplifier with WDM signals The code uses a conventional split-step method to evaluate the signal propagation in the optical fiber while the signal at the amplifier o utput is obtained after having evaluated the gain and amplified spontaneous emission noise contribution by finding the evolution of the excited ion fr action along the doped fiber: As an example, we study a 16 x 2.5 Gbit / s s ystem operating in a link 1000 km long with an amplifier spacing of 100 km.