Contents I. Introduction
With the rapid development of global information traffic, the capacity of optical communication systems is also gradually expanding, in which the symbol rate is continuously upgrading from the original 28GBaud to 220GBaud[1]. Higher symbol rate implies wider frequency band which is needed for the higher speed signal embedded in. In narrowband systems, differential group delay (DGD) between different frequencies is almost constant, which means the polarization mode dispersions (PMD) between different frequency components is strongly correlated. However, in high baud rate systems which is equivalent to wideband system, PMD exhibits to be all-order, in other words, the DGDs between different frequencies is no longer correlated with each other[2]. This leads to larger signal impairment to the higher baud rate systems, resulting in more difficulty to compensate PMD by the DSP algorithms. Therefore, it is necessary to explore an appropriate and simple method to effectively evaluate the PMD impacts on the performance of the different symbol rate optical communication systems in a unified manner.
