THE EFFECT OF BANDWIDTH LIMITED AMPLIFICATION ON SOLITON INTERACTION

A detailed investigation of the effect of bandwidth limited amplificat ion on the Propagation of a single soliton as well as on the interacti on process in soliton trains is performed both numerically and in the framework of a Perturbation approach. Two major effects of the bandwid th limited amplification may be identified, namely the creation and am plification of low-frequency radiation and the shift of the frequencie s of the pulses towards the centre of the filter curve. It is shown th at the initial separation and the strength of bandwidth limited amplif ication determine which effect prevails. Furthermore, we show that the perturbation approach describes reasonably the latter effect whereas the amplification of the low frequency components may lead to soliton instability invalidating perturbation arguments. Eventually, it turns out that the results obtained for two-soliton interaction cannot be ex tended straightforwardly towards N-soliton interaction.