High-power broadband Yb-free clad-pumped EDFA for L-band DWDM applications.

We demonstrated high-power broadband Yb-free clad-pumped erbium-doped fiber amplifier (EDFA) using commercial available low-cost 976 nm multimode diodes. An output power +33 dBm with less than ±1 dB natural gain flatness over a gain bandwidth of 33 nm (1570.3-1603.3 nm) was obtained using a new double-clad erbium-doped fiber which has a large core diameter of 17 μm and low NA of 0.11. The saturated output power, net gain, noise figure, and optical power conversion efficiency of the clad-pumped EDFA were characterized, and system impact of LP11 mode and four-wave-mixing nonlinearity were also evaluated.