Fig. 3.

(a) Matrix of logarithms of the medium’s diffuse reflection coefficient $R_d$; (b) matrix of logarithms of the relative fluorescence level, $R_f$; (c) matrix of logarithms of the ratio of $R_f$ to $R_d$. The data are presented for various absorption coefficients ${\mu }_a$ and reduced scattering coefficients ${\mu }_s^{\prime }$. The region associated with the optical parameters of biological tissues in the near-infrared range is indicated by a red rectangle. The calculation results are presented for an ICG concentration in the medium of $n_0=6.5\times {10}^{-10}\mathrm{M}$, a molar extinction coefficient of ${\epsilon }_0=\mathrm{180,000}{\mathrm{M}}^{-1}·{\mathrm{cm}}^{-1}$, and a fluorescence quantum yield of ${\mathrm{QY}}_0=0.02$.