The gain and optimal length in the erbium-doped fiber amplifiers with 1480 nm pumping

The approximate analytic expressions for the gain and optimal length of the 1480-nm-pumped erbium-doped fiber amplifier with an arbitrary dopant distribution are obtained when the saturation by amplified spontaneous emission (ASE) is neglected. Numerical calculations show that the values predicted from the analytic expressions of the maximal gain and optimal fiber length as functions of input signal and pump powers are very accurate for narrow dopant distributions confined to the center of the fiber core.<
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