Suppression of dynamic instabilities in erbium-doped fiber amplifiers with a combined gain control system

We report an improved transient response of an Er(3+) -doped fiber-optic amplifier with combined electronic feedforward (EFF) and optical feedback (OFB) control systems. We find, theoretically and experimentally, that the time delay of an EFF response leads to control instabilities in the form of erbium-doped fiber amplifier gain auto-oscillations, which can be suppressed by an appropriate choice of OFB wavelength and control system design.