Simulation of phase modulation in EDFAs using an extended model

Nowadays, erbium-doped fiber amplifiers are described by the rate equations for the population densities and the evolution equations of the optical power propagation in the fiber. Since only the power is considered, phase effects like phase modulation and dispersion are not addressed. Here, we present an extended model using a slowly varying envelope approximation that takes into account dispersion and phase modulation. The phase modulation shifts the carrier frequency to a higher frequency. Due to this effect the impulse experiences in a single-mode fiber a different dispersion and, therefore, it should be included for numerical simulations.