Characterisation and modelling of the noise figure (NF) of a praseodymium doped fibre amplifier (PDFA)

An experimental assessment of the gain and noise characteristics of a praseodymium doped fibre amplifier (PDFA) is presented. The experimental data was used to validate a spatially and spectrally resolved amplifier model. The influence of the applied pumping scheme (co-, counter- or bi-directional) obtained from the Amplified Spontaneous Emission (ASE) spectrum on the internal gain and noise figure is shown. The wavelength dependence of both gain and noise figure are well predicted by the amplifier model. Furthermore, the application of the bi-directional pumped PDFA as an optical preamplifier in the receiver is evaluated. The receiver sensitivity improvement is 15 dB. The noise figure directly derived from the system experiments is 9 dB