Impact of hybrid EDFA-distributed Raman amplification on a 4 x 40-Gb/s WDM optical communication system

The impact of hybrid erbium-doped fiber amplifier-(EDFA) distributed Raman amplification on a high bit rate wavelength-division-multiplexed optical communication system is studied by means of a reliable simulation model that takes into account noise properties of Raman amplification. Pure Raman amplification allows the decrease of the mean input power of about 6 dB, keeping the bit error rate at the same level. The best performance, however, is obtained for loss compensation provided by hybrid EDFA/Raman amplifiers, due to the reduction of nonlinear distortion.