Surface Wave Accelerator Based On Silicon Carbide: Theoretical Study

Compact near-field solid-state accelerating structure powered by a carbon dioxide (CO(2)) laser is considered. The accelerating luminous transverse magnetic mode is excited in a few-micron wide evacuated planar channel between two silicon carbide (SiC) films grown on silicon (Si) wafers. Laser coupling to this mode is accomplished through the properly designed Si gratings. Operating wavelength is dictated by the frequency-dependent dielectric permittivity of SiC and the channel width. The geometric loss factor kappa of the accelerating mode is computed. It is found that the unwanted excitation of the guided modes in Si wafers reduces the laser coupling efficiency and increases the fields inside the Si wafer.