基于金属人工表面等离激元的复合型THz硅波导的制备及性能研究

Terahertz integrated waveguide is of significant value in many fields such as on-chip interconnection, information processing and biosensing. Waveguides with Small size, low loss, and multimode can significantly benefit the system integration, signal-to-noise ratio and data transmission capacity. However, current designs of waveguides face certain difficulties in achieving the balance between such performance requirements. In this project, we propose and demonstrate composite THz silicon waveguide based on metallic spoof surface plasmon polaritons, which make full use of the strong electromagnetic field confinement of spoof surface plasmon polaritons based on metal subwavelength structure, as well as the characteristics of low loss and multi-polarization mode of high-resistance silicon waveguide. The project focuses on two key scientific issues: the effective control of waveguide mode and the representation of transmission mechanism. The project would investigate waveguide transmission mechanism, designing of waveguide function and characteristic, and controllable fabrication of waveguides, so that the physical mechanism of the terahertz electromagnetic wave propagation in the composite waveguide could be clarified, which eventually lead to a novel terahertz integrated waveguide that supports multiple polarization mode and strike the balance between loss and integration. The project will provide novel theory and technology for research of terahertz integrated waveguide, and promote the development of terahertz integrated device.

太赫兹集成波导在芯片互联、信息处理及生物传感等众多研究领域有重要的应用价值。小尺寸、低损耗、多模式的波导可显著提高系统集成度、信号质量以及数据传输容量。针对现有的太赫兹波导难以兼顾低损耗与高集成度的不足，本项目提出并研制基于金属人工表面等离激元的复合型太赫兹硅波导。该波导能充分利用金属亚波长结构人工表面等离激元波导的电磁场强局域能力和高阻硅波导的低损耗及支持多种偏振模式特性。项目将围绕复合波导电磁模式有效控制、传输机制精确表征两个关键科学问题，深入研究波导的传输机理、功能特性设计、可控制备和表征，旨在阐明复合波导中太赫兹电磁波传播的物理机理，最终实现支持多偏振模式、可兼顾损耗与集成度性能的新型太赫兹集成波导，为太赫兹集成波导的研究提供新的理论和技术，并推动太赫兹集成器件的发展与应用。

太赫兹波对非极性物质有较强的穿透性，其能量又远小于X射线，人类可以安全接触，使得太赫兹科学技术在通信、雷达、物体成像、医疗诊断、材料分析测试以及环境检测等领域具有广泛的应用。在众多太赫兹技术应用中，小尺寸、低损耗、多偏振模式的太赫兹集成波导可以显著提高系统的集成度、信号质量、数据传输容量，可极大推动相关研究领域的发展。本项目主要研究了太赫兹波段基于高阻硅晶圆制备的低损耗、高集成度波导，波导最低传输损耗可达0.054 dB/cm。同时，本项目针对该类波导与金属波导和天线的耦合方式进行了研究，研制了紧凑型光栅耦合结构。并基于该波导实现了太赫兹波段的集成谐振腔器件，Q值达到2839，进而研究了该谐振腔的微分处理应用。此外，项目组制备了“H-bar”型金属人工表面等离激元波导，并测试了其近场特性。项目中关于波导设计及制备方法的研究成果可为基于该类波导的新型集成太赫兹器件的研究提供支持。