Fig. 2.

Excitation field Φ^x(r, λ) as a function of λ along the z-axis of a 2-cm-wide tissue slab with excitation source located at z=0. The spectral properties (μ_a, ${\mu }_s^{\prime }$) are similar to that of bowel tissue. QDs at locations F and G (see Fig. 3) experience different Φ^x(r, λ_l) for light emission.