Measuring TE1 mode Losses in Terahertz Parallel-Plate Waveguides
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The parallel-plate waveguide (PPWG) has drawn considerable research interest [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12], since it was first reported to support the undistorted propagation of broadband terahertz (THz) pulses. From that time, the transverse-electromagnetic (TEM) mode of the PPWG has been the popular choice for measurements due to its low loss, ease of quasi-optic coupling, and negligible dispersion as a result of the lack of a cutoff. Unlike the TEM mode, the lowest order transverse-electric (TE1) mode has a cutoff frequency, and thus this mode was largely unexplored in the THz regime until recently [13, 14]. This recent work showed that the cutoff frequency could be moved to lower frequencies to reduce the dispersion by increasing the plate separation, while matching the input beam size to the plate separation to realize dominantly single-mode propagation. This same work predicted the possibility of realizing ultra-low ohmic losses in the dB/km range by again...
KeywordsDiffraction Loss Energy Confinement Plate Separation Output Facet Broadband Terahertz
This work was supported in part by the National Science Foundation and by the Lockheed Martin Advanced Nanotechnology Center of Excellence at Rice University (LANCER).