Free electron terahertz source based on dielectric gratings

Terahertz wave sources are essential for the development of terahertz technology. A terahertz radiation source based on dielectric gratings driven by free electrons is proposed in this paper. Electrons emitted by the emitter excite spoof surface plasmons (SSPs) when passing above the structure. Simulation results demonstrate that dielectric gratings enhance the field intensity and electron-structure interaction compared with metal gratings. Additionally, different dielectric materials can be utilized to offer greater flexibility in adjusting radiation characteristics while keeping the structure simple and manufacturable. The use of dielectric materials reduces the metal ohmic loss in the terahertz band. The structure supports on-chip integration, offering a new approach for developing efficient and compact free electron terahertz sources.