Fig. 8. Two-layered tissue phantom experiments representing epithelium and underlying connective tissue.

a Schematic of the two-layered tissue phantom experiment. b Total reflectance signals collected from two-layered phantoms at r₁ = 120 µm (solid lines) and r₂ = 240 µm (dashed lines) source-detector separations for reduced scattering coefficients of the bottom layer µ'_s = 1 mm⁻¹ (red), 1.5 mm⁻¹ (green) and 2 mm⁻¹ (blue). c Reconstructed single backscattering components of the top layer for bottom layers with 1 mm⁻¹ (red), 1.5 mm⁻¹ (green) and 2 mm⁻¹ (blue) reduced scattering coefficients and Mie theory calculations for 0.5 μm diameter polystyrene microspheres in backscattering direction (black line).