Gain modulation response of erbium-doped fiber amplifiers

The small-signal low frequency response characteristics of erbium-doped fiber amplifiers (EDFAs) are examined theoretically and experimentally. Modulating the pump laser results in a low-pass transfer of modulation from the pump to signals amplified in the EDFA. A signal modulated at low frequencies and amplified by an EDFA experiences a transfer function that is similar to that of a lead compensator, which has one zero followed in frequency by one pole. Experimental results verify both the magnitude and phase response of the theoretical transfer functions.<>