Limits for interchannel frequency separation in a soliton wavelength-division multiplexing system

Abstract
We identify the required interchannel frequency separation of the input field for a soliton wavelength-division multiplexing (WDM) system. It is found that the critical frequency separation above which WDM with solitons is feasible increases with the number of transmission channels. Moreover, it is shown that a combination of time- and wavelength-division multiplexing yields the largest transmission capacity. Finally, the structure of the soliton spectra which correspond to the frequency separation smaller than the critical frequency is discussed.