Fig. 1. On-axis phase-shifting PCI-DHM setup based on a Linnik interferometer and experimental results^[30]. (a) On-axial phase-shifting PCI-DHM system based on a Linnik interferometer; (b) phase map of MicroMasch TGZ02 nanostructured test chart with He-Ne laser illumination; (c) phase map of MicroMasch TGZ02 nanostructured test chart with LED illumination

Fig. 2. Principle of the WQPIU with lateral shearing interferometry and phase-shifting interferograms recorded by the CCD camera^[37]. (a) Schematic of the WQPIU; (b) four phase-shifting interferograms recorded by the CCD camera with phase delays of 0, π/2, π, 3π/2, respectively

Fig. 3. Common-path white light phase-shifting interferometer and measurement results^[39]. (a) Schematic plot of the white light phase-shifting interferometer; (b) reconstructed phase image of etched silicon wafer in blue channel; (c) reconstructed phase image of RBC in blue channel

Fig. 4. Principle of full-field resolution optical coherence microscopy^[44-45]. (a) Schematic diagram of experimental setup; (b) OCT image of human left eye

Fig. 5. wDPM system and its spatiotemporal noise stability test results^[46]. (a) Schematic of wDPM; (b) spatial noise distribution in a single frame; (c) spatiotemporal noise histogram in nanometers; (d) spatiotemporal power spectral density in log scale at k_y=0; (e) spatiotemporal power spectral density in log scale at k_y=2π

Fig. 6. iSLIM system and experimental results^[47]. (a) Schematic of iSLIM experimental setup; (b) intensity distribution at the SLM plane imaged by a color camera; (c) SLM transmission mask, in which white represents maximum transmission and black represents minimum transmission; (d) spectrum of halogen lamp (black symbols) and spectral sensitivity of red, green and blue channels of the RGB camera; (e) temporal autocorrelation function of the illumination field, in which τ is the temporal delay and c is the speed of light in water

Fig. 7. Schematic of τ interferometer and quantitative measurement of an RBC^[48]. (a) Schematic of τ interferometer (inset: expanded figure for the reference-beam mirror M₂); (b) quantitative thickness profile of an RBC acquired with τ interferometer in a single camera exposure (left inset: interferogram of the cell; right inset: cross section across the diagonal of the phase profile of the cell)

Fig. 8. Mach-Zehnder interferometer based off-axis PCI-DHM and interference fringes^[57]. (a) Off-axis PCI-DHM based on a Mach-Zehnder interferometer. D, diffuser mounted on an electric motor (not shown); BS₁-BS₂, cube beam splitters; L₁, L₂, and TL, lenses with focal lengths of 250 mm, 250 mm, and 200 mm, respectively; C, condenser lens; OL, objective lens; G, diffraction grating; A, iris diaphragm; (b) interference fringes captured without diffraction grating; (c) interference fringes captured with the grating in place

Fig. 9. An inverted microscope with the LC-SICA module (marked by dashed rectangle) connected to its output and dynamic quantitative phase imaging of a human white blood cell^[28]. (a) An inverted microscope with the LC-SICA module (marked by dashed rectangle) connected to its output; (b) quantitative phase profile of a human white blood cell; (c) quantitative phase temporal standard deviation profile over 150 frames (fluctuation map); (d) quantitative phase values at the three different points marked in Fig. 9(c), in which σ denotes the temporal standard deviations of the quantitative phase values at those points

Fig. 10. Measurement of RBCs and breast cancer cells with multi-wavelength quantitative polarization and phase microscope^[62]. (a) Phase map of RBCs in R channel; (b) 3D images of one cell in the R, G and B channels; (c)--(d) breast cancer cells osmotically swell after exposure to purified water; (e)--(f) breast cancer cells swell and flatten after more purified water were added

Fig. 11. Low-coherence phase-shifting DHM setup and optical section imaging for zebrafish^[64]. (a) Setup of a low-coherence phase-shifting DHM; (b) optical sections of zebrafish tail at z=0, 30, 60 μm; (c) optical sections of zebrafish eye at z=0, 100, 120 μm; (d) reconstructed phase distribution of zebrafish tail at z=60 μm; (e) reconstructed phase map of zebrafish eye at z=100 μm

Fig. 12. Comparison of microstructure measurement results with slightly off-axis DHM based on LED illumination and laser illumination^[66]. (a) Measured profile of the microstructure with LED illumination; (b) measured profile with laser illumination