Quasi-optic terahertz imaging

We demonstrate quasi-optical, diffraction-limited two-dimensional image production by means of reflected pulses of terahertz (THz) radiation. A spherical mirror is used to form a real one-to-one THz image of two 1-mm-diameter steel spheres, which is then scanned over a THz receiver. Diffraction-limited spatial (cross-range) resolution and THz pulse range resolution are simultaneously observed.