New progress of active and passive terahertz imaging

The progress on terahertz imaging at Capital Normal University in Beijing is presented. Our works on Terahertz Imaging include the active and passive imaging. For the active terahertz imaging, the pulse and continue wave terahertz imaging are studied, respectively. The active terahertz pulse imaging is based on the terahertz time-domain spectroscopy with the probe-beam-expanded femtosecond pulse laser and an infrared CCD detection. The active terahertz continuous wave imaging is based on a CO2-laser-pumped terahertz coherent source and a NEC terahertz camera. The active terahertz polarization imaging is studied. For the passive terahertz imaging, the low frequency radiometers are used to detect the beam-scanned terahertz signal by the point-to-point scanning. The related components and image processing methods are developed and used for the improvement of imaging speed and resolution.