Quantitative Modeling of Pulse Amplification in Multimode Cladding Pumped Er-Doped Fiber Amplifiers

We present a new approach in which the nonlinear Schrodinger equation (NLSE) coupled with beam propagation method (BPM) is used to quantitatively simulate pulse propagation in multimode cladding pumped fiber amplifiers. The complexity of fiber structures including fiber shapes and multiple cores which strongly affects the pump propagation and pump absorption and therefore also affects the fiber gain can be described by BPM modeling. The signal gain obtained from BPM is then used for modeling pulse amplification using the standard Step Split Fourier Method (SSFM). The simulation results are in quantitative agreement with our experiments.