Terahertz Digital Holography

Abstract: Terahertz (THz) technology is combined with digital holography for THz imaging. The characteristics of the propagation behaviour of the THz pulse in free space are investigated by using numerical simulations. The algorithm is based on the angular spectrum theory. The spatiotemporal coupling of the THz pulse during propagation results in a significant time‐dependent beam diameter and wave front. The two‐dimensional dynamic evolution of the THz pulse passing through an aperture is obtained. The diffraction is time‐dependent as the pulse travels through the object, which can be clearly observed in simulations. The simulation algorithm and result have been used to reconstruct the original object, with the spatiotemporal amplitude recorded by using a charge‐coupled device (CCD). The implementation of THz digital holography is presented and the corresponding experimental result given.