Study of diffuse reflectance based on a hybrid diffusion approximation and simulating experiment

A modified diffusion approximation is investigated. In this theoretical model, diffusion coefficient D of the standard diffusion approximation is substituted by diffusion coefficient D_asym of P₃ approximation. Analytic solution R_Hybrid(ρ) of this hybrid diffusion for reflectance in single source approximation and steady-state case with extrapolated boundary is obtained; influences of the transport Aledo a' on the standard diffusion approximation R_DA(ρ) and the hybrid diffusion approximation R_Hybrid(ρ) are compared; recovering of optical parameters from diffuse reflectance R_Hybrid (ρ) is demonstrated, and the errors and application ranges are studied. The results show that this hybrid diffusion approximation R_Hybrid (ρ) can be used in strong absorption media and at short source-detector separation.