We experimentally report a high-order-mode (HOM) suppression effect which may bring dips in transmission spectrum of a large-size (with core diameter > 10 µm) six-hole helical microstructured fiber (HMSF). Firstly, we performed rigorous theoretical analysis in helical frame to demonstrate that high loss peaks do not appear in fundamental mode. However, this phenomenon suppressed at special wavelengths is due to coupling rather than the interference between HOMs and air filling mode (AFM). For simplicity, we also proposed a more efficient equivalent structure model which may save much time in simulations based on tangential optical fiber analysis. Theoretical results agree well with experimental results. Furthermore, we introduce a method to effectively manipulate the suppression wavelength by rotating the HMSF axially (without changing the fixed structure parameter). Based on several characteristics of HMSF, we also point its potential in applications such as high-energy laser, optical communication, mode filters and so on.

我们通过实验报告了一种高阶模（HOM）抑制效应，该效应可能导致大尺寸（纤芯直径> 10 µm）六孔螺旋微结构光纤（HMSF）的透射谱出现下降。首先，我们在螺旋框架中进行了严格的理论分析，以证明在基本模式下不会出现高损耗峰。但是，在特殊波长处抑制的这种现象是由于耦合而不是HOM与充气模式（AFM）之间的干扰引起的。为简单起见，我们还提出了一种更有效的等效结构模型，该模型可以在基于切线光纤分析的仿真中节省大量时间。理论结果与实验结果吻合良好。此外，我们介绍了一种通过轴向旋转HMSF来有效控制抑制波长的方法（无需更改固定结构参数）。基于HMSF的几个特征，我们还指出了HMSF在高能激光，光通信，模式滤波器等应用中的潜力。