Simulation of Smith-Purcell terahertz radiation from a dielectric loaded grating

In this paper, with the help of a two-dimensional (2D) particle-in-cell (PIC) code, a simulation of Smith-Purcell (SP) radiation from the dielectric loaded grating is performed in the terahertz regime. The results show that the SP radiation frequency is in good agreement with the theoretical curve. Comparing with the general grating, the usage of dielectric loaded grating enhances the evanescent wave, which can improve the beam-wave interaction, and make the electron beam be bunched more easily.