Average dark soliton dynamics in periodically dispersion compensated fiber transmission systems

We examine the formation and propagation of dark solitons in periodically dispersion compensated (PDC) fiber transmission systems. It is shown that dark solitons in PDC transmission systems are of nonhyperbolic tangent shape and require high background intensity to support. We also find that the amplifier spacing of PDC transmission systems for the dark soliton can be longer than that of the equivalent uniform fiber transmission system with equal path-average dispersion, in contrast to the bright soliton. Other differences and similarities of the dark and bright solitons due to periodic dispersion compensation are discussed as well.