Fig. 1. Schematic illustration of TIR-TDH when the ATRP is vertically tilted.

Fig. 2. Sketch of the actual TIR-TDH system. HWP, half-wave plate; PMs, parabolic mirrors; BS, beam splitter; M, mirror; ATRP, attenuated total reflection prism.

Fig. 3. RI measurement results of a soy wax droplet. (a) Photograph of the sample. (b) Hologram Iobj recorded by TIR-TDH. (c) Spectra of the interpolated hologram. (d) RPV distribution. (e) Corresponding 2D RI distribution.

Fig. 4. RI measurement results of a distilled water droplet. (a) Photograph of sample. (b) Hologram Iobj recorded by TIR-TDH. (c) RPV distribution. (d) Corresponding 2D RI distribution.

Fig. 5. THz RI measurement of an evaporating 75% ethanol droplet. (a) Photographs at different moments. (b) Corresponding 2D RI distributions at 2.52 THz. (c) Changes in the average RI values over time in different regions illustrated in (b). (d) Varied RI data extracted from the white line in (b).

Fig. 6. (a) Orientation of the object beam and reference beam in the coordinates of ξ−η−γ. Simulated off-axis Fresnel holograms when the incident angle of the reference beam is 18° and the pitching angle of the prism is (b1) 3° and (b2) −3°. The red arrows indicate the directions of the holographic fringes. (c1), (c2) Corresponding spectra of (b1) and (b2) shown in logarithmic scale.