Efficient numerical method for predicting the polarization-dependent Raman gain in fiber Raman amplifiers

Polarization-dependent gain (PDG) of fiber Raman amplifiers (FRAs) will degrade the performance of optical communication systems. An efficient numerical model is presented to predict PDG quantitatively by substituting the polarization-dependent polarization factor for the constant one in the coupled nonlinear equations usually adopted. The simulation is carried out by estimating the polarization length by use of the average polarization-mode dispersion of the tested fiber; the results, including the Raman gain-profile and the fluctuation of the PDG, are highly accordant with the experimental data reported previously. The model can aid in the design of FRAs and in the analysis of system performance. (C) 2004 Optical Society of America.