超平坦低色散多孔芯太赫兹波导的优化设计

Optimization design of ultra-flat lower dispersion porouscore terahertz waveguide

以Topas为基材,设计了一种多孔芯折射率引导型超低平坦色散太赫兹微结构聚合物光纤.通过全矢量有限元法结合完美匹配层边界条件,对其有效折射率、约束损耗、有效材料吸收损耗及色散等传输特性进行了分析.结果表明当光纤结构参数选取纤芯椭圆孔的短半轴a=8μm、长半轴b=120μm时,在1.2±0.1 THz的太赫兹频段范围,该光纤呈现一定的低平坦色散特性,其色散值为0.247±0.01 ps/THz/cm,且在频率f=1.2 THz处,其约束损耗和有效材料吸收损耗分别为1.39×10-6 cm-1和0.139 cm-1.所设计光纤呈现的超低损耗和低平坦色散特性以及其简单结构和容易制备等特点将对未来太赫兹波段长距离大容量高速光通信和6G通信技术的发展提供潜在的应用前景.

A porous core index-guided terahertz micro-structure polymer fiber is designed based on background material of Topas.Its transmission characteristics such as the effective refractive index,confinement loss,effective material loss and dispersion are analyzed by adopting full-vector finite element method with the perfectly matched layers.The numerical results indicate that its near-zero low-flattened dispersion of 0.247±0.01 ps/THz/cm can be obtained in the frequency band of 1.2±0.1 THz when the optimal structural parameters is selected as short half axis of a=8μm and the long half axis of b=120μm of elliptical holes in fiber core.Meanwhile,its confinement loss and effective material loss(EML)are 1.39×10-6 cm-1 and 0.139 cm-1,respectively at frequency of 1.2 THz.The proposed waveguide with multiple characteristics,such as low loss and low flat dispersion,and simple structure for fabrication will provide a potential application for the development of terahertz band long-distance high-speed huge-capacity communication and 6G communication technology in the future.