[6]. We will use the parameter x, the
ratio between used pump power and laser threshold power, to evaluate
the extra pump power. In fact the laser threshold power also almost
corresponds to not-clamped OA operation. Working close to the laser
threshold will also generate lower lasing power that will have negligible
impact on the optimum inversion profile along the active fibre (laser
saturates usually one end of output coupler). As a consequence no noisefigure
degradation is observed [8]