Opt Express. 2023 Feb 27;31(5):8855-8863. doi: 10.1364/OE.484330.
In this manuscript, a narrow linewidth fiber amplifier based on confined-doped fiber is established, and the power scaling and beam quality maintaining capabilities of this amplifier are investigated. Benefitted from the large mode area of the confined-doped fiber and precisely controlling the Yb-doped region in the fiber core, the stimulated Brillouin scattering (SBS) and transverse mode instability (TMI) effects are effectively balanced. As a result, a 1007 W signal laser with just 1.28 GHz linewidth is obtained by combining the advantages of confined-doped fiber, near-rectangular spectral injection, and 915 nm pump manner. As far as we know, this result is the first beyond kilowatt-level demonstration of all-fiber lasers with GHz-level linewidth, which could provide a well reference for simultaneously controlling spectral linewidth, suppressing the SBS and TMI effects in high-power, narrow-linewidth fiber lasers.
在本文中，建立了基于受限掺杂光纤的窄线宽光纤放大器，并研究了该放大器的功率扩展和光束质量保持能力。得益于受限掺杂光纤的大模场面积和精确控制光纤芯中的 Yb 掺杂区，有效地平衡了受激布里渊散射（SBS）和横向模式不稳定性（TMI）效应。因此，通过结合受限掺杂光纤、近矩形光谱注入和 915nm 泵浦方式的优点，获得了 1007W 信号激光，其线宽仅为 1.28GHz。据我们所知，这是首例千瓦级以上的具有 GHz 级线宽的全光纤激光器的演示，这为同时控制光谱线宽、抑制高功率、窄线宽光纤激光器中的 SBS 和 TMI 效应提供了很好的参考。
