Excited-state absorption and gain in erbium-fiber amplifiers between 1.05 and 1.35 mu m

Measurements of the transmission of an erbium-doped fiber amplifier in the wavelength range 1.05-1.35 mu m are reported. Excited-state absorption at 1.14 mu m and gain at 1.24 mu m are observed when the amplifier is pumped at 528 nm. There is good agreement between the measured excited-state absorption and gain and that predicted from the energy bands. An excited state absorption between 1.5 and 1.75 mu m is predicted from absorption measurements.<
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