芯泵浦高功率宽带谱平坦长波段光纤光源

为了获得高功率、宽带宽及谱平坦的长波段掺铒光纤光源，基于2级双程芯泵浦，应用偏振复用技术实现泵浦瓦级供给，在泵浦总功率和光纤总长度都不变的情况下，数值分析了4种光源结构的输出特性受泵浦和光纤分配比例的影响。结果表明，4种结构基本都能工作于L波段（1 565 nm~1 610 nm），带宽受结构影响较小，但只有双程后向+双程后向结构可同时拥有高输出功率和高平坦度。其在总泵浦功率750 mW，第一级泵浦功率为300 mW，第二级泵浦功率为450 mW时，和光纤总长度21 m，第一级光纤长度为18 m，第二级光纤长度为3 m时，可实现输出功率314 mW，带宽32.41 nm，中心波长1 584.84 nm，平坦度2.23 dB的L波段超荧光光源。

Core-pumped high-power flattened L-band fiber superfluorescent sources

To demonstrate high-power, broad-bandwidth and spectrum-flattened L-band erbium-doped fiber superfluorescent source (SFS), four different core pumped dual-stage double-pass configurations were proposed based on polarization multiplexing technique, offering Walt-level pump power. The impact of the pumping ratio and fiber length arrangement on the spectrum characteristics including flatness, bandwidth, center wavelength and total output power were numerically investigated with the same total length and total pump power. It shows that four structures can basically work at L band（1 565 nm~1 610 nm） and the bandwidth is less sensitive to structure change. Only the backward-pumped dual-stage double-pass configuration can simultaneously provide high flatness and high output power. A SFS with 314 mW output power, 32.41 nm bandwidth, 1 584.84 nm center wavelength and 2.23 dB flatness can be demonstrated while the total pump power and the pump powers of the first and second stages are 750 mW,300 mW and 450 mW,respectively, and the total fiber length, the fiber lengths of the first and second stages are 21 m,18 m and 3 m,respectively.