Terahertz frequency-selective surface and guided-mode resonance flters

We report on the experimental and theoretical investigation of a new class of terahertz filters based on frequency-selective surfaces patterned on thin foils of the low-loss cycloolefin polymer Zeonor. We observe both broad and narrow-band resonances, which stem from the FSS response and the coupling to substrate guided modes, respectively. The filtering properties are studied as a function of the FSS geometry and the thickness of the polymer layer. Very narrow linewidths with quality factors exceeding 100 are measured experimentally and theoretically confirmed via finite-element simulations.