Though a bolometer or calorimeter is often used as the detector in a CW THz imaging system, they are inconvenient or
time consuming. Whereas a pyroelectric detector is highly desirable for that it can detect CW THz signals with sufficient
speed. In this letter, a THz wave detector based on an infrared pyroelectric senor and its application in CW THz imaging
are demonstrated. A responsivity of over 1200V/W at 1.89THz with the modulation frequency of less than 30Hz is
achieved, and the peak signal to noise ration (SNR) is estimated to be 38dB. With this homemade THz detector and CW
optically- pumped THz laser (OPTL), applications of CW THz imaging are investigated, and a spatial resolution of
about 0.3mm is presented.