High-power fiber lasers have experienced a dramatic development over the last decade. Further increasing the output power needs an upscaling of the fiber mode area, while maintaining a single-mode output. Here, we propose an all-solid anti-resonant fiber (ARF) structure, which ensures single-mode operation in broadband by resonantly coupling higher-order modes into the cladding. A series of fibers with core sizes ranging from 40 to 100 μm are proposed exhibiting maximum mode area exceeding 5000 μm2. Numerical simulations show this resonant coupling scheme provides a higher-order mode (mainly TE01, TM01, and HE21) suppression ratio of more than 20 dB, while keeping the fundamental mode loss lower than 1 dB/m. The proposed structure also exhibits high tolerance for core index depression.

中文翻译：

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大功率激光器用大模面积全固态反谐振光纤设计

在过去的十年中，高功率光纤激光器经历了巨大的发展。进一步增加输出功率需要扩大光纤模式面积，同时保持单模输出。在这里，我们提出了一种全固态反谐振光纤 (ARF) 结构，该结构通过将高阶模式谐振耦合到包层中来确保宽带中的单模运行。提出了一系列纤芯尺寸范围为 40 至 100 μm 的光纤，其最大模式面积超过 5000 μm2. 数值模拟表明这种谐振耦合方案提供了高阶模式（主要是 TE01， TM值01， 和他21) 抑制比超过 20 dB，同时保持基模损耗低于 1 dB/m。所提出的结构还表现出对核心指数下降的高容忍度。