Effects of Self-Saturation in an Erbium-Doped Fiber Amplifier

The dependence of erbium-doped fiber amplifier performance on amplifier self-saturation is studied experimentally by tuning the pump wavelength over a 5-nm band centered at 980 nm. Gain and noise figure are degraded at the peak pump absorption wavelength, which shows the strongest effect of amplifier self-saturation. It is shown experimentally that tuning the pump wavelength away from the peak pump absorption provides 1-2 dB improvement in pump-to-signal conversion. The effect of amplifier self-saturation is also dependent on the signal wavelength where high gain and noise figure penalties are obtained at the 1530-nm (±5 nm) band.