MILLIMETRE AND SUB-MILLIMETRE IMAGING DEVICE

摘要

The terahertz camera has a fixed objective lens (2) and a plurality of detectors (3) positioned at the focal plane of the objective lens (2). Each of the detectors (3) is mounted on a movable support (10) so that the antenna i s capable of movement across the focal plane of the objective lens (2) and is provided with a flexible waveguide (4) for connecting the output of the detector (3) with signal processing means. Each detector (3) is also provide d with a retroreflector (6) which is reflective at frequencies other than terahertz frequencies. During use of the camera, the retroreflector (6) of each detector (3) is illuminated at non-terahertz frequencies so that the spatial position of each detector (3) and hence the spatial source of signal s generated by the detector can be accurately identified. The terahertz camera is particularly suited for use in security installations and in chemical and food processing industries.