5 Gbit/s soliton propagation over 350 km with large periodic dispersion coefficient perturbations using erbium doped fibre amplifier repeaters

Performance limits in optical communications due to fiber nonlinearity

“…Alternative maps were soon also proposed [eg 73] with similar levels of performance. The concept of dispersion management had been proposed and experimentally observed [74,75] for soliton systems, where the benefits of nonlinear transmission combined with anomalous dispersion were fully exploited to eliminate pulse distortion. Whilst concepts such as map strength, first introduced for solitons [76] were eventually applied to non-soliton systems for many years system designers resorted to complete numerical simulations rather than direct calculation of performance limits, and the earliest single channel optically amplified transmission systems employed dispersion management to avoid parametric noise amplification [77].…”

“…The acousto-optic and Raman effects are even more susceptible to dispersion and transmission results over such distances were strongly jitter limited, even at 10 Gbit/s. Due to the strict requirement to achieve specific dispersion coefficients described above, in order to optimize performance at particular bit rates, path averaged dispersion was controlled by the addition of a second, high dispersion, fiber [75]. Including the second fiber was initially carried out simply to tune the mean dispersion, and was basically an experimental convenience.…”

Approaching the Non-Linear Shannon Limit

“…The most predominant non-linear effect arises from the intensity dependent refractive index (Kerr effect) and results in a number of phenomena such as self-phase modulation [41], cross-phase modulation [42] and inter- [43] and intra-channel [44] four wave mixing. Whilst many techniques to mitigate the impact of non-linearity have been developed, including most significantly dispersion management [45][46][47][48][49], the impact of these non-linearities in terms of the information theoretical limits have only recently been addressed [50][51][52]. The key simplification introduced by Mitra and Stark [50] was to equate a non-linear communication channel to a linear channel with multiplicative noise, for which analytical results can be obtained.…”

Recent progress in soliton transmission technology

“…The ''dispersion-managed ͑DM͒ soliton'' technique enables a soliton to propagate even in fibers with normal GVDs as long as the average GVD is kept in the anomalous region. [1][2][3][4][5][6][7][8] The idea of employing dispersion compensation for soliton transmission was first reported in 1991 by Ellis et al 1 and we also reported it independently in 1992 with a view to minimizing pulse broadening and expanding the amplifier spacing. 2 In Ref.…”