Crosstalk caused by fiber nonlinear polarization rotation in DP-QPSK systems

Abstract

The crosstalk caused by fiber nonlinear polarization rotation in Dual-Polarization QPSK (DP-QPSK) system is analyzed, and 100Gbps system is simulated. The results show that the one channel will produce a crosstalk and a ghosting in constellation to another channel, and the rotated angle of crosstalk constellation is proportional to the intensity of influencing signal. When the total input power is less than 4mW, the crosstalk effect can be neglected, otherwise when the total power is more than 20mW, the crosstalk is very obvious. In addition, the crosstalk can't be monitored according to the output eye diagram and SOP in Poincare Sphere in trunk fiber, that make it difficult for the monitoring of optical trunk link.