Terahertz-based Portable Scanner Heads for Multiparameter Sensing Applications

Over the past several years, terahertz (THz) technology has emerged as a critical technique for non-destructive and non-contact measurements in a variety of applications. However, some of the primary challenges in translating THz technology to on-field applications have been the relatively large footprints of the existing systems, the requirements of stringent operation conditions, and the need for customized solutions for specific measurement modes. Such limitations have confined the usability of this technology to laboratory-based applications only. Therefore, in this work, we report compact and lightweight THz-based sensors for multiparametric sensing designed for handheld operation and performing on-field measurements. Further, we demonstrate the broadband standoff spectroscopic sensing capability of handheld devices up to 3.5 THz from a long distance of half a meter (500 mm) from the material. The results show that such customized free-space optics and optimized designs have the potential to lead to a successful translation of THz technology for on-field applications.