Polarization Mode Dispersion Effects on the Multimode Graded-Index Optical Fibers

Light consists of coupled electric and magnetic fields which are spatially and temporally varying periodically. Perpendicular to the direction of propagation, the vectors of electric field can be projected on an orthogonal basis to a horizontal and vertical component. In isotropic media, both components propagate at the same speed and the original polarization of the light is conserved. However, in anisotropic media (physical properties depend on the spatial direction) this is not the case and the two polarization components can travel with different speed causing time delay between the two directions of polarization and thus the dispersion [1, 2].