Comparison of span configurations of Raman-amplified dispersion-managed fibers

We evaluate the performance of dispersion-managed fiber transmission systems employing distributed Raman amplification with 50- and 100-km span length for three different span configurations. The evaluation considers the optical signal-to-noise ratio and the nonlinear phase shift as a measure for the impact of nonlinear effects. The simulation results indicate that a 100-km-long span with the dispersion compensating fiber placed in the span center achieves the best tradeoff between optical signal-to-noise degradation and nonlinear effects.