Fig. 1. Schematic of OSH.

Fig. 2. Two sections together with the real part of the FZPs for each scan.

Fig. 3. Holograms containing two-sectional images of the object with different pupil functions (a), (b) for x0=y0=0 and (c), (d) for x0=0.48  mm, y0=0.

Fig. 4. Sectioning results using (a), (b) the conventional method; (c), (d) the conjugate-gradient-based method with a single measurement; (e), (f) the conjugate-gradient-based method with the proposed method.

Fig. 5. Relationship between x0 and the resolution and the relationship between x0 and the correlation of H1 and H2.

Fig. 6. Relationship between spatial shift and the correlation of H1 and H2.

Fig. 7. Relationship between spatial shift and resolution.

Fig. 8. Object with three sections.

Fig. 9. Holograms containing three-section images of the object with different pupil functions (a), (b) for x0=y0=0 and (c), (d) for x0=0.48  mm, y0=0.

Fig. 10. Sectioning results using (a)–(c) the conventional method; (d)–(f) the conjugate-gradient-based method with a single measurement; (g)–(i) the conjugate-gradient-based method with the proposed method.

Fig. 11. Sectioning results using the proposed method with (a)–(b) Δx=0  nm, z1=34  mm, z2=34.0007  mm; (c)–(d) Δx=100  nm, z1=34  mm, z2=34.0007  mm; (e)–(f) Δx=100  nm, z1=34  mm, z2=34.01  mm.

Fig. 12. Relationship between measurement error and the depth resolution.