Smith-Purcell (SP)辐射是电子沿周期表面运动与慢波互作用产生辐射的现象，辐射波的频率与观测角度有关，是一种可以实现频率可调的小型化太赫兹辐射源；一般情况下辐射频率和角度会随电子速度变化发生改变。Fano共振是一种由两个模式相干涉产生的非对称频谱线形的物理现象，Fano共振超表面具有易于调谐产生高品质因数的特性。为了利用Fano共振高Q值及频率对周期长度变化不大的特性，本项目拟采用SP辐射的机理与Fano共振的优点相结合，发展高效SP辐射的太赫兹源器件。项目将从理论、仿真及实验三个方面，探索Fano共振超表面结构与电子注波互作用的物理机理。通过优化结构提高互作用效率，保持辐射频率不变，通过调谐电子速度控制辐射波方向的目的。解决以往SP辐射波的角度、频率必然会随电子速度变化发生零散的问题，为设计新型的毫米波、太赫兹源提供理论依据与实验基础。

Smith-purcell (SP) radiation is a phenomenon that electrons move along the periodic surface and interact with slow waves to produce radiation. The frequency of radiation wave is related to the observation Angle, and it is a kind of miniaturized terahertz radiation source with adjustable frequency. In general, the radiation frequency and angle will change with the electron velocity. Fano resonance is a physical phenomenon with asymmetric spectral alignment caused by the interference of two modes. The metasurfaces with Fano resonance have the characteristics of easy tuning and high quality factor. In order to take advantages of the high Q value of Fano resonance and the fixed frequency to the period length, this project intends to combine the mechanism of SP radiation with the advantages of Fano resonance to develop a terahertz source device with high efficiency SP radiation. The project will explore the mechanism of interaction between the metasurface structures of Fano resonance and the electron beam from the perspective of theory, simulation and experiment.By optimizing the structure, the interaction efficiency is improved and the electron velocity is changed to control the radiation wave direction with relative fixed frequency.To solve the problem that the angle and frequency of SP radiation wave are necessarily scattered with the change of electron velocity in the past, and to provide theoretical and experimental basis for the design of new millimeter wave and terahertz source.