Enhancing terahertz image quality by finite impulse response digital filter

Terahertz (THz) pulse imaging can provide not only the image, but also the constituent of the detected object. However, various noises from THz source, detector and other parts will decrease the image quality. In this paper, a THz image of a metal hoop was obtained by pulse THz waves, and the finite impulse response digital filter was used to remove the low frequency noise caused by the unstability of THz source and the image quality was improved.