Dynamic compensation of transient gain saturation in erbium-doped fiber amplifiers by pump feedback control

Dynamic compensation of transient gain saturation in erbium-doped fiber amplifiers by pump feedback control is investigated both theoretically and experimentally. It is shown by the theoretical analysis that the gain saturation of 10 dB can be suppressed to less than 0.3 dB if moderately high pump power of 140 mW is available. Furthermore, the required response time of the feedback loop is as slow as 0.5 mu s, which is easily implemented by inexpensive electronics. It is demonstrated experimentally that the transient gain saturation of 3 dB is reduced to 0.3 dB, corresponding to a 10-dB extension of the linear dynamic range of the amplifier.<
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