An output power stabilized erbium-doped fiber amplifier with automatic gain control

Based on the cross-saturation between two different-wavelength optical signals in an erbium-doped fiber amplifier (EDFA), we have developed an output power stabilized EDFA system with automatic gain control. The developed system shows 18.5-dB dynamic range of the output power limitation with the ability to set the output power level arbitrarily. When a temporally varying optical signal is input, the system works as a fluctuation remover for the input signal modulated at low frequency up to 1 kHz and does not have any deteriorative effect on high-frequency modulated optical signals. The degree of modulation in the fluctuated optical signal can be reduced down to as low as 0.003.