Far-field super-resolution millimeter-wave imaging based on waveguide-metalenses

The diffraction limit of traditional millimeter-wave components makes them difficult to break through the wavelength limitation and obtain high-resolution images.Here, we propose a waveguide-metalens, which not only inherits the low loss of waveguides and the far-field imaging of a metalens but also realizes sub-wavelength super-resolution focusing.The imaging method based on a waveguide-metalens combines the integrability and flexibility of waveguides with the phase modulation characteristics of metalenses.By optimization, high-resolution focusing of less than 1/2 wavelength can be achieved at a distance of 4.7 times the wavelength.For verification, we developed a reflective imaging system operating at a frequency near the millimeter-wave atmospheric window (94 GHz), and tested the resolution plate, aerospace ceramics, industrial rubber, and aerospace honeycomb materials.The experimental results are consistent with the theoretical simulations.