gain than in an NZDSF. Figure 14.20 also shows that, in these cases, the multiplex
power d istribution is tilted, but in the opposite direction, due to weaker pump-to-
pump Raman interactions.
Whether the power variations originate from fiber aging or repairs, they have to
be contained. In this resp ect, Raman amplification provides more flexibility than
erbium-doped fiber amplification, because the gain shape can be modified during
the system life by adjusting the pump power of each wavelength of the Raman
amplifier. This could be viewed as an advantage but multiparameter adjustments
add to the complexity of the system. The most straightforwar d way to control these
adjustments would be to rely on optical spectrum monitoring units distributed
along ...