Hand-Guided Mobile Terahertz 3D Imaging Platform with Aspherical Telecentric f-θ Optics

We present a hand-guided mobile terahertz imaging platform for non-destructive testing (NDT). The scanner acquires volumetric 3D image data using an integrated FMCW radar module in combination with a line scanning optics and a position encoder. Consisting of a galvanometer scanner mirror and an aspherical telecentric f-theta lens, the optical system enables B-scans perpendicular to the manual motion over a width of 2 cm. The guiding wheel system of the platform allows precise movement along cracks and welds, for example, enabling the volumetric inspection of the corresponding structures. The platform is optimized for working frequencies of up to 300 GHz. The frequency adaptability of the platform is demonstrated by measurements using a SiGe-chip-based 80 GHz FMCW radar module.