Performance improvement for N × 80-Gb/s WDM transmission link with optimized alternate polarization

In this paper, it is shown that at a high bit rate of 80-Gb/s alternate polarization of adjacent bits in a Wavelength Division Multiplexed (WDM) transmission link improves the system performance in terms of improved Q factor and minimum bit error rate (BER). Alternate Polarization Return to Zero (al-PRZ) further suppresses the non-linear effects at higher power levels of 25 dBm per channel and also improves the transmission length to 640 km for a N × 80-Gb/s WDM system and hence results in an improvement of BER to 10−20.