A novel calculation method for optical amplifier EDFA with multichannel signal and pump sources

Optical amplifier (OA) based on erbium-doped fiber (EDFA, Erbium-Doped Fiber Amplifier) are widely used in optical fiber transmission systems with dense wavelength division multiplexing (DWDM). The design of the optical fiber transmission systems is usually preceded by a simulation, assuming that there are adequate mathematical models of all components. The model of the OA EDFA is a system of ordinary differential equations (ODE) whose solution allows to obtain the power distribution of signals, pumping and noise of amplified spontaneous emission along the erbium doped fiber. The solution of this system is a complex problem, which is due to its stiffness, as well as the specifics of setting the initial conditions, which for different equations are set at different points of the erbium-doped fiber. This paper presents a novel method for the numerical solution of the ODE system, simulating the operation of the OA EDFA, which has a higher calculation speed in comparison with the known methods and takes into account the features of this system.