A Fast Method to Analyze the Fiber Amplifier With the GTWave Pumping Configuration

The pump propagation in the GTWave pumping structure is studied with analytical method and the beam propagation method (BPM). The power distribution function f(ξ) = P
₀
(z)/[P
₀
(z) + P
₁
(z)] is proved to be independent of the fiber core size and the doping content. Based on this f(ξ) function, the propagation of the pump power and the signal power in the fiber amplifier is quickly calculated. With our method, a BPM calculation on a long fiber can be simulated with a highly doped short fiber; thus, the total calculation time is greatly reduced. The analysis of a fiber amplifier with very complicated GTWave pumping configuration is greatly simplified and the calculation speed is accelerated without losing too much accuracy.