The generation of four-wave mixing (FWM) products inside a +30dBm output po
wer booster Er3+/Yb3+ amplifier is reported. The corresponding nonlinear Ke
rr parameter gamma was derived by measurement of the FWM efficiency between
two co-propagating signal pumps. Experimental and theoretical FWM transmis
sion impairments have been confirmed for a 2.5Gbit/s eight-channel WDM tran
smission system.