Fig. 2. The simulation results of NIR bio-tissue imaging via the Monte Carlo method.

Images of a line source through a bio-tissue of 1-mm thickness with scattering anisotropy factor (g) of 0.9, absorption coefficient (μ_a) of 0.3 mm⁻¹, and varying reduced scattering coefficient (μ_s’) (a) μ_s’ = 10 mm⁻¹, (b) μ_s’ = 3 mm⁻¹ and (c) μ_s’ = 0.2 mm⁻¹. Images of a line source through a bio-tissue of 1 mm thickness with g of 0.9, μ_s’ of 1 mm⁻¹ and varying absorption coefficient (d) μ_a = 0.01 mm⁻¹, (e) μ_a = 0.1 mm⁻¹, and (f) μ_a = 1 mm⁻¹. The (g) FWHM and (h) SBR analyses of the samples in (a–f). The light absorption spectra of water within (i) 700–1700 nm³⁸, (j) 700–2500 nm³⁸, and (k) 900–5000 nm³⁹. The gray arrows pointed out the absorption peaks and the gray dashed line in (k) represented the absorbance at 1930 nm. Equivalent images of a line source through a bio-tissue of 1 mm thickness in (l) 1300–1400 nm, (m) 1400–1500 nm, (n) 1500–1700 nm, (o) 1700–1880 nm, (p) 1880–2080 nm, and (q) 2080–2340 nm. The (r) FWHM and (s) SBR analyses of the samples in (l–q).