Abstract The focus of this study was mainly on the birefringence of nanosized bowtie-shaped slot core fibers that can transport ultrasmall optical spots. Here we showed large birefringence for the fibers reaching as high as 0.33, which is three orders of magnitude greater than normal-sized birefringent fibers, the main cause of which being the impact of geometrical birefringence arising from significant differences between the orthogonal modal distributions. Moreover, we investigated the polarization maintaining property for acute-angled bending in a 5- μ m fiber and demonstrated slight degradations of less than 5 dB for the extinction ratio in a 180°bend, which was several orders of magnitude lower than the ratio for the fiber without bending. We used computer simulations for the estimates presented in this study. We believe that the high-polarization maintaining performance presented herein will be required for nanosized optical sensing probes and interconnections in photonic integrated circuits.

中文翻译：

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具有 Si 蝴蝶结纤芯的纳米级光纤的高双折射和偏振保持能力

摘要 本研究的重点主要是能够传输超小光斑的纳米蝴蝶结形槽芯光纤的双折射。在这里，我们展示了光纤的双折射高达 0.33，比正常尺寸的双折射光纤大三个数量级，其主要原因是正交模式分布之间的显着差异引起的几何双折射的影响。此外，我们研究了 5 μm 光纤中锐角弯曲的保偏特性，并证明了 180°弯曲中消光比的轻微退化小于 5 dB，比 180°弯曲时的消光比低几个数量级。光纤没有弯曲。我们使用计算机模拟进行本研究中的估计。