Author Affiliations
1College of Physics and Optoelectronics, Faculty of Science, Beijing University of Technology, Beijing 100124, China2Beijing Engineering Research Center of Precision Measurement Technology and Instruments, Beijing 100124, China3Beijing-Dublin International College, Beijing University of Technology, Beijing 100124, Chinashow less
Fig. 1. Schematic of the experimental configuration of continuous-wave terahertz diffraction tomography (CW THz DT). PM1 and PM2, off-axis parabolic mirrors; BS, THz beam splitter; M, gold-coated mirror; RS, rotational stage.
Fig. 2. Reconstructed results of digital holography for single polystyrene (PS) foam sphere: (a1), (b1) holograms with and without the object at 0°; (c1), (d1) reconstructed amplitude and wrapped phase images of (a1); (a2)–(d2) reconstructed phase images at 0°, 45°, 90°, and 180°; (e1) phase profiles of the black dotted line in (a2)–(d2); (e2) result of (e1) after alignment.
Fig. 3. Reconstructed refractive index (RI) profiles of DT for a single foam sphere: (a1)–(c1), (a2)–(c2) 3D RI profiles at cross sections x–y, y–z, and x–z by FDI and FBPP algorithm, respectively; (d) RI profiles of the red dotted line in (c1) and (c2), and ideal values obtained by the THz-TDS system.
Fig. 4. Amplitude of the spectrum distribution of (a) FDI and (b) FBPP on the logarithmic scale along the fx–fy, fx–fz, and fy–fz cross sections, respectively.
Fig. 5. RI distributions of DT for two foam spheres: (a)–(c) 3D RI profiles at cross sections x–y, y–z, and x–z; (d) volume rendering of 3D RI profiles (see Visualization 1).