3D‐Printed Terahertz Topological Waveguides

Abstract

AbstractCompact and robust waveguide chips are crucial for new integrated terahertz (THz) applications, such as high‐speed interconnections between processors and broadband short‐range wireless communications. Progress on topological photonic crystals shows potential to improve integrated terahertz systems that suffer from high losses around sharp bends. Robust terahertz topological transport through sharp bends on a silicon chip has recently been reported over a relatively narrow bandwidth. Here, the experimental demonstration of topological terahertz planar air‐channel metallic waveguides, which are able to integrate functional components inside the chip, is reported. This platform is fabricated by a simple, cost‐effective technique combining 3D‐printing and gold sputtering. The relative size of the measured topological bandgap is ≈12.5%, which entails significant improvement (≈60%) over all‐silicon terahertz topological waveguides (≈7.8%). Robust THz propagation around defects and delay lines is further demonstrated. This work provides a promising path toward compact integrated terahertz devices as a next frontier for advanced terahertz systems such as wireless communications.