Analytical model for Raman noise figure in dispersion-managed fibers

We derive an exact and a closed-form approximate analytic formula for effective lumped Raman noise figure in backward-pumped dispersion-managed fibers (DMFs) of arbitrary topology. Within the single-pump small-signal amplification model, important effects such as unequal loss coefficients at pump and signal wavelengths or splice loss for the pump and the signal between the DMFs´ sections are taken into account. Theoretical results agree well with the noise figure measured in a symmetric DMF. The developed approach can be used to optimize the noise performance of DMFs.