Gain flattened L-band EDFA based on upgraded C-band EDFA using forward ASE pumping in an EDF section

Abstract
A novel method is presented for implementing an L-band erbium doped fibre amplifier (EDFA) making use of forward amplified spontaneous emission pumping, from a commercially available C-band EDFA, in an erbium doped fibre. Tuning of the length of erbium doped fibre enables a flat gain characteristic to be obtained with a low noise figure over the entire L-band window.