Experimental assessment of wavelength margin in 20 Gbit/s WDMsoliton system over 18 Mm distance

The authors show that the operating wavelength range of a 10 Gbit/s single-channel soliton system using sliding-frequency guiding filters over a 18 Mm distance reduces from 1.3 to 0.2 nm when the system is upgraded to 20 Gbit/s with a second wavelength channel. A record WDM propagation distance >19 Mm is obtained by tuning the channels in the centre of the operating wavelength range. This result is achieved without the use of dispersion management