Mode selectivity of extraordinary optical transmission inside a terahertz parallel-plate waveguide

摘要

We study the dependence of extraordinary optical transmission (EOT) on the input excitation mode by placing a metal screen with a 1D array of holes inside a parallel-plate waveguide (PPWG) operating at terahertz (THz) frequencies. We demonstrate that the output resonant frequency depends strongly on the input mode of the waveguide. We show that the surface plasmon theoretical description is invalid in the case of TE1 mode excitation, and instead use mode matching to properly predict the resonances in both TE1 and TEM. Through this disparity of outcomes between the two different waveguide excitation modes, we can better understand the resonant transmission process.