Polarization behavior in multiply perturbed single-mode fibers

A general theory is presented for polarization evolution characteristics in anisotropic single-mode optical fibers to which plural perturbations of different kinds are applied simultaneously. This treatment is based on modified coupled-mode theory. Polarization performance in the system can be described by a simple projection rule when the birefringence caused by individual perturbation is known. Several examples of applications are classified according to their mode coupling properties in fused silica fibers.