Wavelength Division Multiplexing with Ordinary Solitons

This chapter discusses wavelength-division multiplexing (WDM) with ordinary solitons. There is no net exchange of energy or momentum of solitons after the collisions among ordinary solitons. This transparency makes ordinary solitons ideal for use in dense WDM. But, the loss and varying dispersion of real fibers destroy the symmetries necessary for such transparency, so that the emerging solitons suffer frequency shifts and loss of energy. These defects can be corrected through the use of fibers whose dispersion profile tracks the loss/gain-induced intensity profile. Step-wise approximations to such exponentially dispersion-tapered spans have allowed for successful experimental demonstration of six-channel WDM. The chapter further provides a comparison of the different scaling properties of collisions of ordinary solitons with dispersion-managed solitons. In the experiments described in the chapter, sliding-frequency guiding filters provided a very strong and useful control over the WDM with ordinary solitons in several different ways.