Terahertz Radiation from Grating-Coupled Plasma Waves

In this study, we adopt particle-in-cell simulation to explore a miniaturized high-power terahertz source based on electron beam-plasma interaction with the effect of grating coupler. It is shown that a grating with period of a plasma wavelength can effectively couples the fundamental mode at plasma frequency, and the radiation process includes two platform stages and a decreasing stage due to the phase-space evolution of the electron beam. The present scheme may be useful in the development of miniaturized kilowatt-level coherent terahertz sources.