Amrani Foued, Osório Jonas H, Delahaye Frédéric, Giovanardi Fabio, Vincetti Luca, Debord Benoît, Gérôme Frédéric, Benabid Fetah
GPPMM Group, XLIM Institute, CNRS UMR 7252, University of Limoges, Limoges, 87060, France.
GLOphotonics, 123 Avenue Albert Thomas, Limoges, 87060, France.
Light Sci Appl. 2021 Jan 6;10(1):7. doi: 10.1038/s41377-020-00457-7.
Remarkable recent demonstrations of ultra-low-loss inhibited-coupling (IC) hollow-core photonic-crystal fibres (HCPCFs) established them as serious candidates for next-generation long-haul fibre optics systems. A hindrance to this prospect and also to short-haul applications such as micromachining, where stable and high-quality beam delivery is needed, is the difficulty in designing and fabricating an IC-guiding fibre that combines ultra-low loss, truly robust single-modeness, and polarisation-maintaining operation. The design solutions proposed to date require a trade-off between low loss and truly single-modeness. Here, we propose a novel IC-HCPCF for achieving low-loss and effective single-mode operation. The fibre is endowed with a hybrid cladding composed of a Kagome-tubular lattice (HKT). This new concept of a microstructured cladding allows us to significantly reduce the confinement loss and, at the same time, preserve truly robust single-mode operation. Experimental results show an HKT-IC-HCPCF with a minimum loss of 1.6 dB/km at 1050 nm and a higher-order mode extinction ratio as high as 47.0 dB for a 10 m long fibre. The robustness of the fibre single-modeness is tested by moving the fibre and varying the coupling conditions. The design proposed herein opens a new route for the development of HCPCFs that combine robust ultra-low-loss transmission and single-mode beam delivery and provides new insight into IC guidance.
近期对超低损耗抑制耦合（IC）空心光子晶体光纤（HCPCF）的显著展示，使其成为下一代长距离光纤光学系统的有力候选者。对于这一前景以及诸如微加工等短距离应用（需要稳定且高质量的光束传输）而言，一个阻碍是设计和制造一种兼具超低损耗、真正稳健的单模性以及保偏操作的IC引导光纤存在困难。迄今为止提出的设计方案需要在低损耗和真正的单模性之间进行权衡。在此，我们提出一种新型的IC-HCPCF以实现低损耗和有效的单模运行。该光纤具有由Kagome管状晶格（HKT）组成的混合包层。这种微结构包层的新概念使我们能够显著降低限制损耗，同时保持真正稳健的单模运行。实验结果表明，对于一根10米长的光纤，一种HKT-IC-HCPCF在1050纳米处的最小损耗为1.6分贝/千米，高阶模消光比高达47.0分贝。通过移动光纤和改变耦合条件来测试光纤单模性的稳健性。本文提出的设计为开发兼具稳健超低损耗传输和单模光束传输的HCPCF开辟了一条新途径，并为IC引导提供了新的见解。
