The Influence of Ripple Depth and Ripple Taper on Bandwidth and Centre Frequency Shift Operating at Terahertz Frequency in a Coaxial Bragg Structure

Based on the mode-coupling method, comparative study is carried out for the influence of different ripple depths and different ripple angles on bandwidth and centre frequency shift characteristics operating at THz high-frequency coupling mode. The results show that the bandwidth of the working mode and the competing mode increases with the increase of the slot depth, but the centre resonance frequency almost does not shift; With the increase of the slope angle, the centre frequency of the working mode almost does not shift, while the centre frequency of the competing mode will be far away from the centre frequency of the working mode, and the farther the deviation is with the increase of the slope angle. These characteristics are conducive to better suppress the band gap overlap and construct the Bragg structure with single high-order mode at THz frequency.