Monaco polarization-maintaining fiber optic cable G 654 E

Several different designs are used to create birefringence in a fiber. The fiber may be geometrically asymmetric or have a refractive index profile which is asymmetric such as the design using an elliptical as shown in the diagram. Alternatively, permanently induced in the fiber will produce ; this may be accomplished using rods of another material included within the cladding. Several dif. [PDF]