Fig. 1. A multi-layered medium model with semi-infinite thickness of biological tissue

Fig. 2. Comparison of P3 equation with Monte Carlo simulation and diffuse equation. (a) Five-layer medium; (b) six-layer medium; (c) relative error of six-layer medium when absorption coefficient is low; (d) relative error of six-layer medium when absorption coefficient is high; (e) comparison of different absorption coefficients and thicknesses; (f) fat and muscle tissue

Fig. 3. Comparison of P3 equation with Monte Carlo simulation and diffuse equation. (a) Six-layer medium; (b) relative error of six-layer medium when μ_a1=…=μ_a6=0.001 mm^-1; (c) relative error of six-layer medium when μ_a1=…=μ_a6=0.01 mm^-1

Fig. 4. Comparison of P3 time domain equation with Monte Carlo simulation and diffusion equation. (a) Five-layer medium; (b) six-layer medium; (c) near peak value of five-layer medium; (d) near peak value of six-layer medium; (e) relative error of five-layer medium; (f) relative error of six-layer medium; (g) comparison of high absorption coefficients; (h) relative error in high absorption coefficients; (i) comparison of different absorption coefficients and thicknesses; (j) fat and muscle tissue