0.1THz super-resolution imaging based on 3D printed confocal waveguides

Abstract The paper reports a waveguide-based lens-free terahertz (THz) imaging method. It not only inherits the advantages of traditional confocal imaging, but also realizes super-resolution in THz band. The waveguides prepared by a 3D printing and metal-cladding technology can replace the traditional lens to transmit and focus THz wave effectively. For verification, two hollow waveguides (8 mm inner diameter, 60 mm length) were fabricated and a 0.1 THz confocal waveguides imaging system was built. High quality THz images with a minimum resolution of 1.41 mm (less than 1/2 of the wavelength) were obtained by placing the imaging targets at the waveguide’s focus and performing two-dimensional scanning. The focusing mechanism and transmission characteristics of THz in the waveguide are simulated and analyzed. The simulations are in agreement with the experiments.