Frequency multiplexing/demultiplexing using additive-manufacturing-based devices for terahertz networks

In this research, we present the design, fabrication and experimental validation of 3D printed mux/demux elements for terahertz frequencies. The devices consist of a set of in-line polystyrene (PS) rectangular waveguides, separated by 100 μm, 200 μm and 400 μm air gaps. The principle of operation for the proposed elements resides in coupled-mode theory. Q-factors of up to 3.4 are observed, and additionally, the experimental evidence demonstrates that adding fibers to the design improves the Q-factor by up to 0.62 per fiber added. Using two independent THz broadband channels, we demonstrate the first mux/demux device based on 3D printed in-line filters for the THz range. This approach represents a fast, robust and low-cost solution for the next generation of THz devices for communications.