Suppose 50 m of erbium fiber is uniformly pumped to provide a net gain of 1 dB per meter for a small signal (ls = 1

Physics Jan 19, 2021

Suppose 50 m of erbium fiber is uniformly pumped to provide a net gain of 1 dB per meter for a small signal (ls = 1.55 µm). Assume the fiber has a 4 µm mode field diameter for a Gaussian mode, Isat = 6000 W/cm2 (lp = 1.48 µm), Er3+ spontaneous lifetime is 3 ms, and G = 0.7. What is the average output power from the amplifier if the average input power of a pulse train is (a) 1 µW (b) 20 µW (c) 1 mW