A Review of the Concept, Applications and Implementation Issues of Terahertz Spectral Imaging Technique

Simultaneous spectral and spatial information of any object investigated through electromagnetic radiation leads to the concept of spectral imaging technique (SIT): in terahertz (THz) range, because of limited opacity of various dielectrics, this technique gets further accentuated by "through-barrier" SIT. In this review, we revisit the fundamental physics, important domains of applications and issues with experimental implementations and required image analyses of this technique in THz band. The suitability of THz-SIT in various real-world scenarios are discussed, especially with respect to spectral noise arising out of presence of barriers, long times required for image acquisition, limited portability and customizability of systems based on such technique.