Fig. 2.

Comparison between the analytical two-layered model and MC simulations for $L_1$ (a, d), $L_2$ (b, e) and $L_T$ (c, f) in a homogeneous medium, for three thicknesses of layer 1: $l_1=$ 6 mm, $l_1=$ 12 mm and $l_1=$ 18 mm. In the latter (c, f), the theoretical model for a completely homogeneous medium (taken from Ref. [22]) is also shown. Upper row: ${\mu }_{a,1}={\mu }_{a,2}=$ 0.0067 ${\mathrm{mm}}^{-1}$ . Lower row: ${\mu }_{a,1}={\mu }_{a,2}=$ 0.018 ${\mathrm{mm}}^{-1}$ .