Lossless polarization attraction simulation with a novel and simple counterpropagation algorithm for optical signals

We introduce a simple and fast iterative algorithm, named SCAOS (simple counterpropagation algorithm for optical signals), for simulating the counterpropagation of optical signals within a nonlinear fiber. Being based on the split-step Fourier method, the algorithm is easily implementable in many traditional optical simulators. Applications of the SCAOS algorithm to the vectorial nonlinear counterpropagation of a polarized pump and a probe signal demonstrate the phenomenon of lossless polarization attraction. The evolution of the signal polarization along the fiber, obtained by simulation, reveals that polarization attraction always entails a certain amount of degradation of the signal’s degree of polarization. Two different setups are studied, involving different types of fibers with Kerr nonlinearity, and highlighting the dependence of the attraction phenomenon, as well as of its effectiveness, on the fiber type.