A new, to the best of our knowledge, hollow-core optical fiber based on a tube lattice geometry is proposed. The fiber cross section is formed by eight tubes with five different thicknesses, and the guidance mechanism is based on the inhibited coupling phenomenon. As such, its transmittance spectrum displays low-loss windows intercalated with high-loss regions, each of the latter related to specific core-cladding modal couplings. The spectral behavior of the straight and bent waveguide is numerically analyzed. Simulations on different curvature radii and directions (angles) show the core mode displacement toward the outer side of the curvature and its impact on the spectral shift of the high-loss wavelengths. The different response of each tube resonance is investigated and discussed. The proposed structure identifies a new and promising path for the development of directional curvature sensors.

中文翻译：

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方位角不对称管状格子空心光纤

据我们所知，提出了一种新的基于管点阵几何结构的空芯光纤。纤维横截面由五个不同粗细的八根管子组成，引导机制基于抑制耦合现象。因此，它的透射光谱显示低损耗窗口插入高损耗区域，后者中的每一个都与特定的纤芯-包层模态耦合有关。对直波导和弯曲波导的光谱行为进行了数值分析。对不同曲率半径和方向（角度）的模拟显示了向曲率外侧的核心模式位移及其对高损耗波长光谱偏移的影响。研究和讨论了每个管共振的不同响应。