In this paper, we demonstrate a switchable transverse mode operation fiber laser. Lasing in a specific transverse mode is enabled by employing a Fabry–Prot (F-P) cavity forming an external feedback cavity architecture as an effective transverse mode selector. High spatial quality tunable output modes, including vector vortex beam, orbital angular momentum (OAM) vortex beam and flat-topped beam, could be achieved by optimizing the cavity length and appropriate polarization control. The purity of the vector vortex beam is more than 95%. The topological charge of the OAM mode can be tuned from −1 to +1. The purity of the 1 OAM vortex beams are all more than 95%. The normalized root mean square of the flat-topped beam is 0.035 and the steep degree is 0.815. Furthermore, this approach has great scalability and can be applied to other modes and spectral regimes.

在本文中，我们展示了一种可切换的横模操作光纤激光器。通过采用 Fabry-Prot (FP) 腔形成外部反馈腔结构作为有效的横向模式选择器，可以实现特定横向模式下的激光。通过优化腔长和适当的偏振控制，可以实现高空间质量可调输出模式，包括矢量涡旋光束、轨道角动量 (OAM) 涡旋光束和平顶光束。矢量涡旋光束纯度在95%以上。OAM 模式的拓扑电荷可以从 -1 调整到 +1。1 OAM涡旋光束纯度均在95%以上。平顶梁的归一化均方根为 0.035，陡度为 0.815。此外，