We propose and experimentally demonstrate a multi-wavelength erbium-doped fiber laser (EDFL) with orbital angular momentum (OAM) mode output. Employing a Mach–Zehnder filter, a Sagnac loop filter, and a mode-selective coupler, the proposed EDFL achieves single-, dual-, triple- and quadruple-wavelength outputs of OAM modes. The tunable range of the output wavelengths is up to 22.64 nm. Besides, the multi-wavelength laser is able to emit OAM modes with its topological charge of $ \pm {1}$. The proposed EDFL has the advantages of wide wavelength tunability, good stability, high signal-to-noise ratio (higher than 34 dB), and high mode purity (up to 95%), which may be applied for mode-division-multiplexing optical communication and optical fiber sensing systems.

中文翻译：

---

可调轨道角动量模式输出的多波长掺fiber光纤激光器

我们提出并通过实验证明了具有波长角动量（OAM）模式输出的多波长掺fiber光纤激光器（EDFL）。提议的EDFL使用Mach–Zehnder滤波器，Sagnac环路滤波器和模式选择耦合器，可实现OAM模式的单，双，三和四波长输出。输出波长的可调范围高达22.64 nm。此外，多波长激光器能够以其拓扑电荷$ \ pm {1} $发射OAM模式。所提出的EDFL具有波长可调性广，稳定性好，信噪比高（高于34 dB）和高模纯度（高达95％）的优点，可用于模分复用光学。通信和光纤传感系统。