Abstract We demonstrate a highly efficient, broadband fiber-optic intermodal converter. The technique relies on a long period grating mechanically induced in a two-mode fiber. A compact, portable apparatus was designed and fabricated, where period-variable metallic corrugation is implemented to form periodic micro-bends along the fiber. The coupling strength between the interacting fiber modes and the grating period can be tuned continuously and individually using two control knobs in the apparatus. Experimental results show that the complete coupling between the LP01 and LP11 modes is achieved, which is confirmed by an observed over-coupling while increasing the grating strength. For the short fiber length of

中文翻译：

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高效宽带光纤机械联运转换器

摘要 我们展示了一种高效的宽带光纤多模转换器。该技术依赖于在双模光纤中机械诱导的长周期光栅。设计并制造了一种紧凑的便携式设备，其中实施了周期可变的金属波纹，以沿光纤形成周期性的微弯曲。相互作用的光纤模式和光栅周期之间的耦合强度可以使用设备中的两个控制旋钮连续和单独调谐。实验结果表明，实现了 LP01 和 LP11 模式之间的完全耦合，这通过观察到的过耦合同时增加光栅强度得到证实。对于短纤维长度为