ANALYSIS OF DYNAMIC PUMP-LOSS CONTROLLED GAIN-LOCKING SYSTEM FOR ERBIUM-DOPED FIBER AMPLIFIERS

Amplified multiwavelength optical communication networks are prone to substantial cross-gain modulation induced signal power fluctuations wh en channels are turned on/off or rerouted. This perturbs amplifier gai ns at other wavelengths and can cause service impairment not known in electronically switched networks. In this letter, we analyze the recen tly proposed and experimentally tested inversion and gain-locking tech nique for erbium-doped fiber amplifiers (EDFA's), based on pump power loss monitoring. A large-signal numerical model which incorporates tim e variation effects, the downstream propagation of signal and pump and both the downstream and upstream propagation of amplified spontaneous emission has been used for the analysis, It follows from the theoreti cal investigation that the surviving channel power excursion in a sing le 20-dB gain EDFA can be reduced to 0.3 dB in case of addition/remova l of six channels in an eight-channel multiwavelength system when the pump power feedback parameters are appropriately selected.