Finally, we note a remarkable general scaling property of PMD analyzed by
Shtaif and Mecozzi [17] as a general property of the Brownian motion nature of
PMD in long fibers [4]: when normalized to the mean DGD, all PMD curves of
long fibers are statistically equivalent in a certain sense. That is, if one stretched a
10-nm horizontal patch of data in Figure 17.2 into the full scale, and reduced the
vertical scale by 10, the resulting curves would be valid representations of another
fiber with a DGD 10 times smaller, a point that has significant system implica-
tions. The wide variation s in Figure 17.2 lead one to expect that its DGD distribu-
tion reasonably approximates the “true” Maxwellian distribution and provides a
good estimate for the mean