Terahertz imaging by THz→IR conversion

A low-cost THz→IR converter based on a printed metasurface is fabricated. The converter is a thin membrane which absorbs the terahertz radiation at a single frequency using a grating of antennas, and converts it into thermal IR radiation. Here, we demonstrate THz imaging at 96 GHz using an IR camera equipped with the converter. The membrane can be upgraded to convert simultaneously multiple frequencies thus giving a possible path for terahertz multispectral imaging using an IR camera.