Laplacian pdf of DGD time derivative and application to predicting PMD-induced outage rates

It is reported for the first time that the time derivative of differential-group delay (DGD) on buried fibres has a Laplacian pdf. Using this, the previously reported expression for predicting the polarisation-mode dispersion (PMD)-induced outage rate is simplified and it is shown that it is a function of the mean DGD and the fibreʹs Laplacian parameter only.