Terahertz Resonances of Transverse Standing Waves in a Corrugated Plate Waveguide

Abstract

Terahertz (THz) propagation in periodic structures has attracted great attention because of its captivating electrical and optical properties. However, the created THz band gaps are usually considered to be caused by Bragg resonances. Here, we theoretically and numerically investigate THz resonances and their related band gap properties in a periodically corrugated plate waveguide with arbitrary wall profiles. It has been found that the corrugated structure can cause not only the interaction between the same transverse modes, called the Bragg resonance, but also the strong interference between different transverse standing wave modes, which occurs in a higher frequency range with quite different features. Unlike the well-known Bragg resonance, the excited resonances between different transverse modes can produce the stronger energy attenuation and wider frequency band gap. The dispersion diagram is depicted to clearly describe the relationship between these resonances and waveguide geometries. Using this method, we can properly estimate the band gap structure of THz waveguides, which has been confirmed by the simulated results. In addition, these two resonances can be easily manipulated by changing the symmetry of waveguide structures. These findings on THz propagation in periodic waveguides could be applicable in high performance devices, such as filters, modulators and switches.

Antisymmetric localization of terahertz defect modes in a planar waveguide with undulated walls

“…The dispersion curves in figure 3(a) break off in the frequency range of 1.43-1.50 THz, which means that the perfect periodicity of the structures causes the corresponding resonance at the breaking point, thereby suppressing the transmission of THz waves. The splitting position is away from the boundary of the first Brillouin zone with β = ±K/2, which can be identified as non-Bragg resonance induced by the interaction of different transverse modes [48]. As expected, an obvious forbidden band can be observed at the corresponding frequency range in the transmission spectrum with steep band edges, as shown by the purple dotted line in figure 3(b).…”

“…To effectively predict the band gap properties of the corrugated waveguide, according to the previous theoretical results [48], we propose a dispersion diagram by depicting the references for the dispersion curves in the first Brillouin zone in figure 2 with some marked special points. The references for the dispersion curves have been defined as…”

Reflective Metasurface With Steered OAM Beams for THz Communications

“…For a long time, terahertz (THz) applications were confined to imaging and sensing as pertinent to the scarcity of high-efficiency THz devices [1]. However, the rapid development of THz technologies has attracted attention to the THz gap (between 100 GHz and 10 THz) to be used in several applications associated with security, astronomical observation, and localization [2], [3], [4]. Nevertheless, the growth of the world's hunger for higher data rates and low latency wireless communications will deplete the available frequency resources [5], which has motivated researchers to resort to the THz regime.…”