"Building on previous theoretical work, a research team at the University of Sussex, U.K., has demonstrated a prototype camera that uses nonlinear “ghost” imaging to perform hyperspectral imaging in the terahertz frequency band (Optica, doi: 10.1364/OPTICA.381035). The researchers believe that the camera, which reportedly can capture terahertz field details at a subwavelength scale, could open up a range of applications in security, bioimaging, manufacturing and more."

Link