At a receiver a 20 Gbit/s soliton bit stream (20) is demultiplexed into
two 10 Gbit/s bit streams (22a, 22b) using a 2-way
splitter (6), a clock extraction circuit (4), and a pair of polarization
insensitive amplitude modulators (8a, 8b) exhibiting
positive chirp. The outputs of the modulators are fed to detectors (7a,
7b) via lengths (9a, 9b) of optical
fiber exhibiting normal dispersion thereby producing bit streams (23a,
23b) with increased mark/space ratio and reduced timing jitter.