Subwavelength diameter micro/nanofiber (MNF) provides excellent platform for many applications. In this work, we fabricate subwavelength diameter MNFs with ultra-long waist and analyze the propagation loss origin for such fibers. Transmittance as high as 99.4% is measured for MNF with a waist length of 10 cm and diameter of 1.2μm1.2\mu \text{m} , and the loss is mainly resulted from the modal leakage of the taper. However, when the MNF is getting longer and thinner, the intrinsic surface roughness induced during the fabrication process overrides the modal leakage and plays a major role in the propagation loss. Our study reveals existence of an ultimate transmission limitation for ultra-long MNFs.

中文翻译：

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低损耗超长亚波长微/纳米光纤


亚波长直径微/纳米光纤（MNF）为许多应用提供了出色的平台。在这项工作中，我们制造了具有超长腰部的亚波长直径 MNF，并分析了此类光纤的传播损耗来源。腰长10 cm、直径1.2μm1.2\mu \text{m}的MNF测得透过率高达99.4%，损耗主要由锥体的模态泄漏造成。然而，当 MNF 变得越来越长和越来越薄时，制造过程中产生的固有表面粗糙度会覆盖模态泄漏，并在传播损耗中发挥主要作用。我们的研究揭示了超长 MNF 存在最终传输限制。