Fig. 4.

Analyses of the absorption and reduced scattering spectra. (a) An absorption coefficient spectrum ${\mu }_a(\lambda )$ for a phantom containing scattering TDP and absorbing CBP with concentrations of 0.1% and 0.0055% (w/w), respectively, and fit to a wavelength-dependent linear function, ${\mu }_a(\lambda )=c·\lambda +d$. The gray area represents an uncertainty bound ($k=1$) of experimental data. (b), (c) Plots of the fitted parameters $(a,b,c,d)$ versus CBP concentration. (d) A reduced scattering coefficient ${\mu }_s^{\prime }(\lambda )$ for the same sample as in (a) and fit to a wavelength-dependent power law function, ${\mu }_s^{\prime }(\lambda )=a{(\lambda /500)}^{-b}$. The gray area represents an uncertainty bound ($k=1$) of the experimental data. (e), (f) Fit parameters ($a$, $b$, $c$, and $d$) versus TDP concentration (e) and (f). In (b) and (e), linear fits to the parameters $d$ and $a$, respectively, are shown along with slopes and CODs of the linear fits.