Investigation of C-band pumping for extended L-band EDFAs

In this study, we present systematic numerical and experimental analysis of high-power C-band light pumping in extended L-band erbium-doped fiber amplifiers (EDFAs). We investigate, for the first time to the best of our knowledge, how C-band light sources can be used as pump sources to extend the bandwidth of L-band EDFAs beyond 1610 nm. Results show that, when using a C-band light source as the sole pump, efficient amplification is obtained over the extended L-band, but at the expense of a higher noise figure. However, the advantage of C-band pumping in terms of power conversion efficiency can be exploited when using a two-stage EDFA, with a first stage pumped by 1480 nm to maintain good noise figure performance and a high-power C-band light source (up to several hundred mW) as the pump source for the second stage. Thus, a 20 dB gain covering 1570–1618 nm with a maximum noise figure of 5.7 dB is demonstrated.