Factor of Two Improvement of Extended L-Band EDFA by Re-flecting Out-of-Band ASE

Extended L-band amplification in erbium-doped fibers is inherently inefficient as it utilizes the tail of the gain spectrum. This work demonstrates, via experiments and simulations, a significant gain improve-ment of 3.28 dB by reflecting only 1 % of the out-of-band amplified spontaneous emission.