PMD emulator using non-uniform probability distributed state of polarization

Due its stochastic behavior, the polarization-mode dispersion is one of most difficult fiber effects to simulate. It is not easy to randomly change the temperature and pressure in laboratory and the correct relation between this changes and light polarization is fuzzy yet. Therefore the most common way to study PMD is through the use of devices called PMD emulators. The main problem with this emulators is the large number of elements used to precisely reproduce the random nature of PMD. This paper reviews the most common technique to build in a PMD emulator based on the concatenation of birefringent elements, and proposes an alternative way to achieve the first order statistics presented in the literature using only two elements.