Xlim, UMR 6172 CNRS, University of Limoges 123 Avenue A. Thomas, 87060 Limoges, France.
Opt Lett. 2010 Jul 1;35(13):2233-5. doi: 10.1364/OL.35.002233.
Very large-mode-area Yb(3+)-doped single-mode photonic bandgap (PBG) Bragg fiber oscillators are considered. The transverse hole-burning effect is numerically modeled, which helps properly design the PBG cladding and the Yb(3+)-doped region for the high-order mode content to be carefully controlled. A ratio of the Yb(3+)-doped region diameter to the overall core diameter of 40% allows for single-mode emission, even for small spool diameters of 15 cm. Such a fiber was manufactured and subsequently used as the core element of a cw oscillator. Very good beam quality parameter M(2)=1.12 and slope efficiency of 80% were measured. Insensitivity to bending, exemplified by the absence of temporal drift of the beam, was demonstrated for curvature diameter as small as 15 cm.
我们研究了超大模场面积掺镱（Yb(3+)）单模光子带隙（PBG）布拉格光纤振荡器。数值模拟了横向孔烧蚀效应，这有助于合理设计 PBG 包层和 Yb(3+)掺杂区，以精细控制高阶模含量。Yb(3+)掺杂区直径与整个芯径的比值为 40%，即使在 15 cm 小的线轴直径下也可以实现单模发射。制造了这样的光纤，并随后将其用作连续波振荡器的核心元件。测量到非常好的光束质量参数 M(2)=1.12 和 80%的斜率效率。对于曲率直径小至 15 cm 的情况，表现出对弯曲的不敏感性，例如光束没有时间漂移。
