160 km transmission was 0.75 ps. For the 2.56 Tb/s transmission, shorter pulses are
desirable. However, the reduction of the pulse width in the present set up was
limited by the bandwidth of the cascaded non-gain-flattened EDFAs, fourth-order
CD and higher order PMD.
For 2.56 Tb/s transmission, the system performed nearly error- free (BER
10
9
) in the back-to-back configuration and revealed BER values 10
5
after
160 km transmission. BER values <10
4
result in an effective BER < 10
12
if
standard FEC (assuming a 7% overhead) is used. This FEC would reduce the
payload to 2.4 Tb/s. For 1.28 Tb/s, error-free (BER< 10
9
) transmission was
obtained. At this data rate, error-free transmission was also possib le over a fiber
link of 240 km Ultrawave
TM
fiber