It was observed that the constant saturated output power range, called dynamic range, of a two-stage erbium-doped fiber amplifier (EDFA) employing an optical bandpass filter depends on pump powers of the first stage EDFA, and the saturation power level depends on pump powers of the second stage EDFA. Low noise figure configurations of the first stage amplifier in the two-stage EDFA turn out to deliver low gain efficiencies and narrow dynamic ranges. The measured unsaturated gain, saturated output power, and dynamic range of the two stage EDFA were 51.5 dB, 13.8 dBm and 30 dB within 1 dB of the peak value, respectively, at the first and second amplifiers' pump powers of 13 mW and 51 mW.
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