A solution of an YDFA in tandem-pumping configuration with ASE using RK4 method

A new solution for a tandem amplifier is presented using a fiber doped with ytterbium and a core coating ratio of 30/250 and which incorporates the solution of the rate equations with the amplified spontaneous emission characteristic in these multi-kilowatt systems. The model describes in a more precision way the behavior of a fiber amplifier with a 5. 986kW,1018nm pumping and a signal seed of 75W, 1080nm, solving the propagation and rate equations using the fourth-order Runge-Kutta as well the relaxation methods as a convergence criterion for the integrations.