Terahertz imaging and recognition systems

In this study, imaging of concealed metallic objects on human body at Terahertz (THz) frequencies by a stand off distance (3m – 10m) is investigated. THz waves, which are appropriate for imaging purposes on safety, medical, non-destructive inspection, etc. because of penetration through lots of materials and vibration of some molecules, cover the region between 0.1 THz and 10 THz in the electromagnetic spectrum. The need to use transmitter or THz sources have disappeared in passive imaging method, which uses the cosmic background radiation caused by the reflections of the THz radiation and is also preferred for its simple structure, applicability and non-radiating property. A quasi-optic imaging system with insulating lens and low noise THz detector with pre-amplifier have been realized for experimental studies, beside investigations on quasi-optic THz imaging systems, mechanical scanning systems and low noise THz detector structures. This study is the first experimental study conducted on our country about Terahertz imaging and the THz images obtained from the experimental system reveal availability of THz waves for imaging.