Comparison of soliton transmission schemes incorporating lumped fibre amplifiers

Soliton transmission through cascaded fibre amplifiers has attracted widespread attention recently. Two transmission schemes, namely, "average soliton method" and "preemphasis method", were proposed to propagate solitons through such a transmission link. We compare the two methods by studying the soliton propagation behavior along a number of optical amplifier stages. Numerical simulation has shown that the preemphasis method works reasonably well only under certain conditions and require relatively small amplifier spacings. If these conditions are violated, the preemphasis method leads to soliton deterioration. However, the average soliton method maintains quite good soliton transmission stability even when these conditions are somewhat relaxed. The distance between optical amplifiers in the latter method can be made considerably longer.<>