Design and numerical analysis of hollow-core negative curvature fiber for transmission in terahertz waveband

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Dec.2023, Vol.46 No.12: 1722-1728

DOI: 10.3969/j.issn.1003-5060.2023.12.021

Authors

CHEN Wu, GAO Weiqing, LUO Qiaoxia, CHEN Kai, ZHANG Kai, WANG Xian

(School of Physics, Hefei University of Technology, Hefei 230601, China)

Abstract and Keywords

Abstract: A hollow-core negative curvature fiber (NCF) based on cyclic olefin copolymer (COC) is designed. The effects of structural parameters such as fiber core diameter, tube diameter and capillary thickness on the confinement loss of NCF are analyzed, and the parameters are optimized. The simulation results show that the confinement loss of single-cladding NCF is $ 10^{-4}-10^{-5} $ dB/m in the frequency range of 2.0-2.5 THz, and the minimum confinement loss is reduced to $ 8.90 \times 10^{-5} $ dB/m. By introducing the inner cladding tube to destroy the symmetry of the conventional NCF, the fiber core mode is coupled with the cladding capillary mode, which increases the difference in refractive index and loss in the polarization directions of x and y to produce birefringence. The factors affecting birefringence and confinement loss of NCF are analyzed. The birefringence can reach $ 10^{-4}-10^{-5} $ in the frequency range of 2.0-3.0 THz. The simulation results provide a new way for long distance transmission and polarization sensitive applications of terahertz NCF.

Keywords: negative curvature fiber(NCF); terahertz waveband; optical fiber design; confinement loss; birefringence

作者信息

陈吴，高伟清，罗巧霞，陈凯，张凯，王贤

（合肥工业大学物理学院，安徽合肥230601）

摘要和关键词

摘要: 文章设计了一种基于环烯烃共聚物（cyclic olefin copolymer，COC）的空芯负曲率光纤（negative curvature fiber，NCF），分析结构参数光纤芯径、管径和毛细管厚度对光纤限制损耗的影响，并对参数进行优化，使得单包层NCF在2.0～2.5 THz频率范围内限制损耗为 $ 10^{-4}\sim10^{-5} $ dB/m，损耗最低值可降到8.90× $ 10^{-5} $ dB/m；引入内包层管破坏常规负曲率光纤的对称性，使纤芯模式与内包层管壁模式进行耦合，从而增加x和y偏振方向的折射率和损耗差异产生双折射；对影响光纤双折射特性和限制损耗的因素进行分析，在2.0～3.0 THz频率范围内双折射系数可达到 $ 10^{-4}\sim10^{-5} $。该文结果为太赫兹NCF的长距离传输、偏振敏感等应用提供了一条新的途径。

关键词: 负曲率光纤（NCF）；太赫兹波段；光纤设计；限制损耗；双折射

Funding

国家自然科学基金资助项目（61875052；61905059；62105087；62105088）；安徽省重点研发计划资助项目（202104a07020010）；安徽省自然科学基金资助项目（1908085QF273；2018085QF273；2108085QF282）和中央高校基本科研业务费专项资金资助项目（JZ2020HGTB0065；JZ2021HGTA0145；JZ2021HGQA0255；JZ2021HGTA0148）

合肥工业大学学报(自然科学版)

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