Passive THz imaging system for stand-off identification of concealed objects:Results from a turn-key 16 pixel imager

Passive imaging of concealed objects at stand-off distances in excess of a few meters requires both excellent spatial, thermal and temporal resolution from the terahertz imaging system. The combination of these requirements while keeping the overall system cost at a reasonable level has been the motivation for this joint work. The THz imaging system under development is capable of sub-Kelvin NETD at video frame rates. In this paper we report the first imaging results from a 16-pixel array of superconducting antenna-coupled NbN vacuum-bridge microbolometers, operated within a cryogen-free, turn-key refrigerator. In addition to the system overview, we shall also address the uniformity of the detectors and present passive indoors raster-scanned imagery