Study Of Dispersion-Managed Soliton Propagations

Optical solitons in fibres are formed by a balance of group velocity dispersion(GVD) and Kerr non-linearity, as we all know. At present Numerical simulation and experiments have demonstrated that solitons can propagate an extended distance without distortion, so they may become the ideal message carrier in a long-distance communication. However, periodical compensations are necessary for fibre losses and the dispersion in optical fibres in which optical soliton pusle is transmitting, such as optical amplification and dispersion-managed compensations. Meanwhile, there are many perturbations in a practical soliton system, which lead to the fluctuation in amplitude or pulse-width, and deform the shape of soliton. So Their effects can't be neglected in soliton communication system, such as degrading the stability of coherently amplified solitons, increasing the time jitters in arrival, and reducing the capacity. The dispersion-managed-soliton(DMS) transmission techniques are produced to resolve the above-mentioned problem.In this paper, the models of periodic perturbations with periodical group velocity dispersion map are built in the dispersion-managed soliton system, firstly their effections on various soliton propagation with third-order dispersion periodicity variaty are investigated numerically. The results show, time delay of soliton versus propagation distance will linearly arise mainly, and the effects independently exist. We can obtain the mean values of effects by third-order dispersion along propagation distance. Secondly the models of periodic perturbations with second-order dispersion periodicity variaty are made in the dispersion-managed soliton system, we numerically show that there are not only many extremums but also switch characteristic in dependence of the propagation distance on the period lengths of perturbations, so we can control the propagation of soliton more benefically than ever.