Fig. 1. Schematic of LF-TDH coordinate system.

Fig. 2. Schematic of LF-TDH experimental layout.

Fig. 3. Siemens star and its LF-TDH reconstruction results. (a) Photograph of the sample. (b) Accumulated hologram of 500 frames. (c1) Reconstructed amplitude image after a single inverse Fourier transform of (b). (c2) Reconstructed amplitude image after DC term filtering and apodization from (c1). (d1), (d2) The reconstructed amplitude images before and after correction, respectively. White scale bars represent 3 mm.

Fig. 4. LF-TDH reconstruction results of a PP plate. (a) Photograph with schematic pattern. (b1)–(b3) Hologram, the corresponding reconstructed amplitude and phase images, respectively. (b4) The cut-profile of the blue line plotted in (b3). (c) Expanded amplitude distribution by stitching 20 images. (d) The 3D thickness profile distribution of the sample by stitching unwrapped phase images.

Fig. 5. Dynamic observation results of an aquatic leaf (Hottonia inflata) based on LF-TDH. Photographs of the leaf (a1) before and (a2) after data acquisition. Reconstructed (b) amplitude and (c) phase results. The 3D profile distributions at (d1) the begining and (d2) the end of data acquisition. Black and white scale bars represent 3 mm.

Fig. 6. (a) Reference points (black dots) and different-colored rectangular regions are chosen to estimate (b) the movement of leaf of Hottonia inflata and to represent the changes of (c1), (c2) amplitude, (d) phase, and (e) water content under the illumination of 2.52 THz CW beam. The colored dots represent experimental data, and the black lines represent the fitting results. The green curves are the mean values on the full leaf.