Low-Loss Terahertz Corrugated Fiber Waveguide with Metal Inner Coating

We propose a flexible metal-inner-coated corrugated fiber waveguide designed for low-loss terahertz (THz) wave transmission in the 140–290 GHz range. Simulation results demonstrate that the proposed waveguide achieves propagation losses of 0.028–0.075 dB/m, representing a 70% reduction compared to metal-inner-coated waveguides with a smooth interior surface of the same core radius. Additionally, numerical analysis indicates that for a core radius of 4 mm, the bending loss at 185 GHz is 0.1023 dB/m under a 20 cm bending radius.