Waveguide-based reflective super-resolution THz imaging

Here we describe a novel reflective confocal scanning method for super-resolution terahertz (THz) imaging. The traditional continuous-wave THz confocal method is difficult to break through the diffraction limit owing to the Abbe limit. So, it's difficult to achieve super-resolution images, especially in low frequency THz wavebands. Besides, the traditional terahertz lens system has a large loss, so it cannot achieve long-distance transmission and imaging. In this paper, low-cost and low-loss terahertz waveguides are printed to replace conventional lenses. Through the reasonable design of the waveguide, we can breaks through the diffraction limit and achieve sub-wavelength focusing, so as to achieve super-resolution terahertz imaging. The final experimental resolution is less than half of the wavelength.