将太赫兹波束缚于亚波长区域是减小器件尺寸、提高成像分辨率、增强传感灵敏度的重要途径。目前通常采用伪表面等离子体技术实现太赫兹波的亚波长限域。然而该方法难以消除光场束缚产生的金属损耗。本项目提出利用一维介质光栅中的布洛赫表面波实现对太赫兹波的亚波长限域和低损耗传输的新思路。探讨光栅的结构参数对太赫兹表面波的色散曲线的影响规律，通过优化光栅结构同时提高太赫兹波的传输距离和束缚程度。重点研究光栅表面金属粒子的等离激元共振与布洛赫表面波模式耦合的作用机制，揭示共振耦合对太赫兹表面波传输行为的影响。在此基础上，通过共振耦合调谐太赫兹表面波的模场分布、传输损耗和束缚深度，实现对太赫兹表面波的传输特性的有效调控。本项目有望解决太赫兹表面波无法同时实现较强的亚波长束缚与减小的传输损耗的难题，推动太赫兹亚波长器件向产业化方向的深入发展。

Confining the THz wave in subwavelength region is an important rout to reduce the device sizes, improve the imaging resolution and enhance the sensing limit of THz wave. Generally the spoof surface plasmon polariton is employed to guide the THz wave within subwavelength regions.Yet by this means, it is difficult to eliminate the Ohmic losses caused by the confinement effect. This project proposes a new strategy to enhance the subwavelength bounding effect while reducing the transmission losses of THz wave based on the bloch surface wave in the one dimensional dielectric grating. We will investigate the Influence of structural parameters of the grating on the dispersion relation of THz surface wave. And by optimizing the grating structure, we aim to improve the transmission distance and the bounding effect of the THz wave simultaneously. The project is mainly focused on analyzing the coupling mechanisim between the bloch surface wave and the localized surface plasmon resonance of metallic particles. The impact of mode coupling on THz transmission will be revealed. This mode coupling will be utilized to adjust the field distribution, transmission losses and near-field confinement of THz wave, which in turn leads to effective manipulation of transmission characteristics of the THz wave. If smoothly implemented, the project might overcome the difficulty of simultaneously realizing the strong confinement and low losses of the THz surface wave. And it is expected to motivate the potential industrial applications of THz subwavelength devices.