A tunable universal terahertz filter using artificial dielectrics based on parallel-plate waveguides

摘要

Using parallel-plate waveguides u0002PPWGsu0003 that mimic artificial dielectrics, we demonstrate anuniversal filter that provides low-pass, high-pass, band-pass, and band-stop u0002or notchu0003 filteringnfunctionalities in the terahertz u0002THzu0003 frequency regime. The device essentially consists of twonPPWGs in a complementary geometry. The filtering functionality is achieved by positioning annappropriate amplitude mask in the path of the spatially chirped THz beam between the twonwaveguides. By varying the position of the mask, we experimentally and theoretically demonstratencontinuous tunability of the respective 3 dB cutoff frequencies within the frequency range fromnabout 0.3 to 0.7 THz.