The realization of terahertz image reconstruction with high resolution based on the amplitude of the echoed wave by using the phase retrieval algorithm

An indirect imager working at terahertz band is presented and implemented, which is suitable for high-resolution planar object detection. The proposed imager employs a simple quasi-optics design to transmit and to receive terahertz waves, and adopts incoherent detection technology to extract the intensity of echoed signal, which results in a relatively low complexity and cost. Moreover, the Fienup Fourier phase-retrieval algorithm is successfully modified and is applied to retrieve the phase of the echoed signal and reconstruct the target image. Imaging experiments on typical planar objects are performed with the imager working at 0.2 THz, and the experimental results demonstrate the good performance of the proposed imager and validate the effectiveness of the reconstruction algorithm.