Experimental demonstration of soliton transmission over 28 Mm using mostly normal dispersion fiber

We report on stable soliton propagation experiments in a fiber transmission system consisting of more than 90% normal dispersion fiber. The transmission system has a dispersion map much like that used in nonreturn-to-zero (NRZ) pulse transmission but with a path-average anomalous dispersion of +0.1 ps/nm-km. A stable soliton pulse train at 8 GHz has been observed after 28 Mm of propagation in a 108-km recirculating fiber-optic loop. A significant enhancement in the average soliton power required for stable transmission in a dispersion map with alternating signs of dispersion is experimentally demonstrated for the first time. Theoretical modeling of our experiment is in good agreement with our findings.