Study On Terahertz Functional Components Based On Metal Surface Plasma Polaritons And Terahertz Coupling Structure

With the rapid development of terahertz (THz) sources and detectors, THz technology developed rapidly. The THz components need to be further developed to promote the researches and applications of THz science and technology. Metal surface plasmon polaritons (SPPs) can break diffraction limit and restrict the electromagnetic waves to be transmitted at sub-wavelength scale. Spoof SPPs can be achieved on metal films with groove arrays.A new type of terahertz component is presented in this paper. It consists of two parallel metallic plates with rectangular groove arrays on their inside surfaces. Surface plasmon polaritons controlled entirely by the surface geometry can be excited by incident terahertz waves when a metallic surface is periodically corrugated. The simulation results show that the fundamental wave guide mode of the parallel metallic plates change into surface wave mode and arise a band gap between this mode and other wave guide modes. The band-stop filtering functionality is realized by rejecting all frequencies in the gap. Transmission spectra also show zero transmission within the band gap region. By improving this structure, it can be use as a terahertz band-stop filter and narrow band-pass filter.It can be found that the researches of many components merely stay in the design stage, their measured characteristics are not good enough with high difficulty of coupling. THz couplers will be discussed in this paper through simulation and experiment. A new type of coupler based on SPPs will be discussed.