Fig. 1. Schematic diagram of interferometry principle

Fig. 2. Schematic diagram of non-continuous wavenumber sweeping

Fig. 3. Geometric illustrations of optical path differences. (a) Λ₅₆; (b) Λ₅₇; (c) Λ₆₇

Fig. 4. Simulated wavenumber sequence and interference patterns. (a) Discontinuous scanning wavenumber sequence; (b) interference pattern; (c) longitudinal section of interference pattern taken at x_p=500 pixel

Fig. 5. Spectral cross-section evaluation of interference pattern at y_p=500 pixel and interference point signal at (500 pixel, 600 pixel). (a) Interference signal demodulated using Fourier transform with wavenumber bandwidth Δk₁; (b) interference signal demodulated using Fourier transform with wavenumber bandwidth Δk₁+Δk₂; (c) interference signal demodulated using least squares spectrum with wavenumber bandwidth Δk₁+Δk₂

Fig. 6. Interference phase wrapping and unwrapping diagrams when OPDs are Λ₅₆ and Λ₅₇. (a)(e)(i)(m) Ideal phase diagrams; (b)(f)(j)(n) interference phases derived from interference signal with wavenumber bandwidth Δk₁ using Fourier transform demodulation; (c)(g)(k)(o) interference phases derived from interference signal with wavenumber bandwidth Δk₁+Δk₂ using Fourier transform demodulation; (d)(h)(l)(p) interference phases derived from interference signal with wavenumber bandwidth Δk₁+Δk₂ using least squares spectrum demodulation

Fig. 7. Multi-surface scanning interferometry hardware system. (a) Optical path diagram; (b) experimental setup diagram

Fig. 8. Experimental interference patterns. (a) Interference pattern; (b) longitudinal section of interference pattern taken at x=1.91 mm

Fig. 9. Spectral cross-section evaluation diagram of interference pattern at y=1.91 mm and interference point signal at (1.50 mm, 1.91 mm). (a) Experimental interference patterns with frame numbers of 1‒90 demodulated by Fourier transform; (b) experimental interference patterns with frame numbers of 1‒400 demodulated by Fourier transform; (c) experimental interference patterns with frame numbers of 1‒400 demodulated by least squares spectrum

Fig. 10. Interference phase wrapping and unwrapping diagrams of front and rear surfaces of optical wedge. (a)(e)(g)(j) Interference patterns with frame numbers of 1‒90 demodulated by Fourier transform; (b)(f)(k)(n) interference patterns with frame numbers of 1‒400 demodulated by Fourier transform; (c)(f)(i)(l) interference patterns with frame numbers of 1‒400 demodulated by least squares spectrum

Fig. 11. Interference phase wrapping and unwrapping diagrams of front and rear surfaces of plano-convex lens. (a)(e)(g)(j) Interference patterns with frame numbers of 1‒90 demodulated by Fourier transform; (b)(f)(k)(n) interference patterns with frame numbers of 1‒400 demodulated by Fourier transform; (c)(f)(i)(l) interference patterns with frame numbers of 1‒400 demodulated by least squares spectrum

Fig. 12. Multi-surface measurement results. (a) Three-dimensional fitting of front and rear surfaces of optical wedge; (b) error distribution map of planar surface of plano-convex lens; (c) three-dimensional fitting of convex surface of plano-convex lens