Performance Limitations of an Optical IM-DD Transmission System Due to Polarization Mode Dispersion

An analytical approach is presented to evaluate the impact of polarization mode dispersion on the average bit error rate (BER) performance of a intensity modulated direct detection (IM-DD) optical transmission system considering Maxwellian distribution for the differential group delay (DGD). The results show that the performance of an IM-DD system suffers power penalty of 0.27 dB, 0.45 dB and 2.4 dB corresponding to mean DGD of 20 ps, 35 ps and 40 ps respectively at a BER of 10 operating at a bit rate of 10 Gb/s. Furthermore, at increased values of the mean DGD there occur BER floors above 10 which can not be lowered by further increasing the signal power. It is noticed that BER floors occur at about 2x10, 10 and 10 corresponding to mean DGD of 45 ps, 50 ps and 60 ps respectively at 10Gb/s. The effect of PMD is found to be more detrimental at higher bit rates.