pulse broadening due to polarization mode dispersion and chromatic dispersion in optical fiber communications

Both chromatic dispersion (CD) and polarization mode dispersion (PMD) participate in pulse broadening during the propagation in single mode fibers. The study of CD effects on the pulse shape need to know only the transfer function that describes CD for optical fiber, whereas the study of PMD effects need to know the principal states of polarization, state of polarization, differential group delay, in addition to the transfer function that describes PMD. In this paper, we set a new theory to study the effects of the two types of dispersion simultaneously on the shape of the propagated pulse. We find that the CD effects are the dominant in a certain cases, while in other cases the PMD effects are the dominant.