Analysis of Erbium-Doped Fiber Amplifiers Pumped in the sup 4 I sub (15/2) - sup 4 I sub (13/2) Band.

A theoretical model for Er sup (3+) -doped fiber amplifiers pumped within the particular sup 4 I sub (13/2) - sup 4 I sub (15/2) absorption band is developed. The model predicts gain coefficients around 2 dB per mW of launched pump power, in close agreement with previously reported measurements. The model is also used to determine the optimal pump wavelength lambda sub (opt) that maximizes the amplifier gain. It is shown that the latter is insensitive to pump detuning within a 20 nm range near lambda sub (opt) = 1.48microns, which indicates that broadband multimode laser diode pump sources and pumps with narrow linewidths should yield identical gain performance.