A comparative study of an erbium doped fiber amplifier pumped at 811 and 980 nm

The gain and saturation characteristics of an erbium doped fiber amplifier pumped in both the 800 nm and 980 nm pump bands are presented. The maximum gain coefficients are found to occur at the same fiber lengths for both 811 nm and 980 nm pumping. They are 1.2 dB/mW and 7.8 dB/mW, respectively. The amplifier thresholds at both pump wavelengths are quantitatively compared using a simple model and measured attenuation coefficients. Signal amplification at 1533 nm is found to suffer more from the effects of excited state absorption than signal amplification at 1553 nm