L-band EDFA gain and gain flatness enhancement via co-propagating C-band seed technique

We present a novel L-band EDFA design and its optimization based on co-propagating C-band seed technique. This technique provides over 30 dB gain with a moderate NF (< 5.5 dB) within 32 nm bandwidth in a single stage amplifier. We also show that simulation results are consistent with the experimental measurements.