Passive real-time submillimetre-wave imaging system utilizing antenna-coupled microbolometers for stand-off security screening applications

At present, the imaging of concealed weapons and contraband is primarily carried out at a relatively short stand-off range of a few meters mainly because of spatial resolution considerations. In order to maintain a reasonable aperture size, there is a desire to extend the operating frequency towards 1 THz. In this paper we report the progress on a video-rate THz camera demonstrator which utilizes broadband antenna-coupled microbolometers as detectors, operated within a turn-key commercial closed-cycle cryocooler. A full system has been integrated consisting of 64 parallel sensors and readout electronics, and reflective Schmidt camera optics incorporating a conical scanner for real time imaging. At present, the system provides near real time submillimetre-wave video imagery at 6 frames per second.