3-D analysis of terahertz frequency multiplier excited due to interaction of convection electron beam and surface waves (Smith-Purcell effect)

In this paper, we present a three dimensional numerical study on a terahertz frequency multiplier. The process of frequency multiplication is proposed via study of spontaneous Smith-Purcell (SP) radiation. Through introducing a single electron bunch perturbation which is passing over above a metallic grating, and due to interaction of electron bunch with surface wave, the evanescent wave radiates from the ends of the grating and the SP radiation is generated in the span of 0.466∼1.1 THz. We found that the maximum of SP radiation amplitude is distributed around 90° with the centre frequency 0f ∼0.65 THz. Simulations on the generation of SP radiation at THz frequencies have been performed with the help of the 3D particle-in-cell (PIC) finite integral method and results agree very well with analytic ones.