Noise figure of erbium doped fiber amplifiers in the saturated regime

We have made an experimental and theoretical study of the noise figure of an erbium doped fiber amplifier in the saturated regime. The saturated amplified spontaneous emission at the signal wavelength was measured using a very accurate pulsed source technique. We have quantified the noise figure dependence on compression, in excellent agreement with theory, to be less than 1.5 dB for a gain compression as high as 15 dB when the small signal gain was 26 dB, and the 1.48 μm pump power was 27 mW.