<title>Erbium-doped fiber amplifier (EDFA) noise figure computation for saturated and unsaturated regimes</title>

Abstract

This paper is divided in two parts. The first one is dedicated to the noise figure computation of noise saturated EDFA. In-line and preamplier EDFA are mainly concerned. The noise figure calculation requires the computation of the whole ASE spectra. A discretization of the fluorescence spectrum is detailed in order to rapidly and accurately compute the EDFA noise. The gain and noise values obtained with our method have been compared to those of various European research laboratories: there is no meaningful (< 1%) differences between our results and methods which consider the fluorescence at every nanometer. The same numerical accuracies are obtained leading to smaller computation times. In the second part, the noise figure of booster EDFA is investigated. In the case of booster EDFA, the input signal is quite high (a few mW). The laser levels populations are dependent on the photon number. The now classical noise figure formula have to be carefully applied because of this dependence. A direct integration of the master equation is required to compute the real noise figure of power boosters. The discrepancies between both definitions have been quantified: differences up to 3 dB have been computed for a 980 nm-forward pumped EDFA.