Meta-waveguide-based computed tomography for terahertz super-resolution imaging

A lens-free terahertz computed tomography method based on metamaterial waveguide (meta-waveguide) is proposed. In this method, the meta-waveguide replaces the traditional terahertz lens or mirror. It not only inherits the low-loss transmission performance of the waveguide but also breaks through the diffraction limit and achieves subwavelength focusing. Its focusing distance is greater than the Rayleigh length, which is helpful for Radon scanning and tomography imaging. The focusing and transmission characteristics of terahertz in meta-waveguide are analyzed, and the principle of meta-waveguide-based computational tomography system is presented. Then, a 3D printing and copper plating method was proposed for processing the meta-waveguides. Finally, a 0.1 THz Radon tomography scanning system was established. High quality terahertz images with a resolution of 1/3 of the wavelength were obtained, and the three-dimensional image of biological tissue (artificial blood vessel) was acquired.