THz Diffraction Radiation Analysis of Finite Graphene Strip Grating with Grounded Dielectric Substrate Excited by Electron Beam

We consider THz range diffraction radiation (DR) of a harmonically modulated electron beam passing above graphene-strip grating on dielectric substrate with perfectly electric conducting (PEC) ground plane. We assume that the electron velocity is fixed. The problem is reduced to a singular integral equation (SIE) with additional conditions. The Nystrom-type algorithm is used for SIE discretization. The used approach allows to obtain numerical results with controlled accuracy. We show that maximum radiation is observed near the plasmon resonances. However, the grating-mode resonances can spoil DR.