Wavelength division multiplexing in an unfiltered soliton communication system

The limits on the minimum and maximum channel spacing of an unfiltered wavelength division multiplexed soliton communication system are examined. It is shown that soliton frequency shifts due to collisions at the receiver limit the minimum channel spacing to about four soliton spectral widths while the gain deviation among different channels sets a limit on the maximum channel spacing. The gain mismatch tolerance is determined.