We report 2.5 Tb/s (64 x 42.7-Gb/s) WDM transmission over 4000 km (forty
100-km spans) of non-zero dispersion-shifted fiber. This capacity x distance record
of 10 petabit-km/s for 40-Gb/s systems is achieved in a single 53-nm extended L band
using return-to-zero differential-phase-shift-keyed modulation, balanced detection,
and distributed Raman amplification.
© 2002 Optical Society of America