The Enhanced Third Harmonic Superradiation of Smith Purcell Terahertz radiation source

Here we propose a new method to enhance the third harmonic of superradiant Smith-Purcell. In this paper, the specific designed grating structure enhances the power of the third harmonic by suppressing the second harmonic. Therefore, the higher frequency radiation signal (25 mW, 326 GHz) is generated by the lower energetic electron beam (9 keV)passing through the grating with larger size (0.4 mm), compared with normal superradiation by using PIC simulation. Accordingly, this mechanism is expected to achieve more efficient compact and tunable terahertz radiation sources with higher frequency.