Arrays

The images of Figure: Indoor Image were obtained with a slow single pixel imager. Although at a fundamental level rapidly scanning single pixel imagers can have a S/N advantage over array based systems (largely because the illuminating power can be focused on the pixel being observed) [1] they are difficult to implement at video frame rates. A successful approach to video frame rate imaging is based on a 120 element microbolometer array. This system is capable of producing signal comparable in strength to the much more elaborate and expensive MMIC amplifier arrays [2].

Figure: Indoor Image. (a) An indoor image of a
face made with a passive bolometer system centered
on ~650 GHz and (b) an image of a face made with
an active illuminator and heterodyne receiver at 632
GHz.

References

  1. Grossman, E. N., Luukanen, A. & Miller, A. J. Terahertz Active Direct Detection Imagers. Terahertz for Millitary and Security Applications II 5411, (2004).
  2. Luukanen, A., Miller, A. J. & Grossman, E. N. Active millimeter-wave video rate imaging with a staring 120-element microbolometer array. Radar Sensor Technology VIII and Passive Millimeter-Wave Imaging Technology VII 5410, (2004).