Simultaneous polarization mode dispersion and chromatic dispersion monitoring method in 40 Gbit/s system by polarization modulation

A simple method to monitor CD and PMD simultaneously is proposed and implemented by using two polarization-modulation pilot tones with different frequencies. It has been theoretically derived and experimentally verified that RF output power increases with GVD and DGD in sin/sup 2/ relation, and power ratio of the two pilot tones increases with GVD and decreases with DGD, thus CD and PMD can be distinguished and monitored simultaneously.