L-Band Bismuth-Based Erbium-Doped Fibre Amplifier

Characterization study of Bismuth-based Erbium-doped Fibre (Bi-EDF) and its performance as gain medium for L-band Erbium-doped Fibre Amplifier (EDFA) is studied. Bismuth oxide glass host enables very high erbium doping concentration without significant concentration quenching effect. The Bi-EDF studied is only 2.15m long with Erbium ion concentration of 3,250 wt. ppm. corresponding to a maximum absorption coefficient of 157.61dB/m at 1530nm. With optimum excitation, Bi-EDFA exhibits small signal gain bandwidth of over 70nm ranging from 1550nm to 1620nm. Maximum signal gain per length coefficient at 1580nm for Bi-EDFA is 12.7dB/m. A 56nm 3dB gain bandwidth with average gain of 18.6dB is achieved. Improvement on the small signal gain performance of Bi-EDFA is demonstrated in a two-stage EDFA configuration. By utilizing C-band ASE generated by Bi-EDFA as pump source for a second stage EDF, maximum small signal gain improvement of 5.0dB over the single stage Bi-EDFA is observed.