Wavelength division multiplexing with solitons in ultra-long distance transmission using lumped amplifiers

One attractive feature of the all-optical approach to ultra long-distance transmission is that it greatly facilitates wavelength division multiplexing (WDM). It is known that solitons of different velocities are transparent to each other. It is shown, through numerical simulation, that such transparency is also maintained in a system using lumped amplifiers, as long as the length of the collision (the distance the solitons travel down the fiber while passing through each other), is long enough relative to the spacing between amplifiers, or to a possibly longer period of variation in some other parameter, such as the fiber´s chromatic dispersion. This result implies the potential for at least several multigigabits-per-second WDM channels spanning just 1 or 2 nm, in a system of transoceanic length (7000-9000 km)