Soliton robustness to polarisation dispersion pulse broadening in a 400 km
installed optical fibre is experimentally demonstrated. With 10ps input pul
ses and a differential group delay of 7.6ps, the soliton pulsewidth at the
receiver is maintained within 10-11ps when the input polarisation is change
d, while the corresponding range for dispersion-compensated linear pulses i
s 10.5-15.5ps.