Role of distributed amplification in designing high-capacity soliton systems.

We discuss the importance of distributed amplification for high-speed soliton communication systems through numerical simulations by considering the distributed gain provided by stimulated Raman scattering or erbium dopants. Hybrid amplification schemes are also considered. At a bit rate of 40 Gb/s, the use of distributed amplification is found to improve the transmission distance (deduced from the Q parameter) by a factor of up to three for Raman amplification and >5 for erbium dopants, compared with the case of lumped amplifiers. The increase in transmission distance is by a factor of about two for 80-Gb/s soliton systems when dense dispersion management is used.