Fig. 3

All possible combinations of interaction events during path sampling in a scattering fluorescent mixture. The white/green events represent an interaction between the light ray and non-fluorescent/fluorescent volume samples. The events in (a) and (b) are not physically-plausible because a fluorescent emission must occur at a fluorescent sample. f is also not possible because λ _m cannot excite the dyes to emit at λ _x . The events in (c), (d), (g) and (h) represent an elastic scattering at the same wavelength. e is the only event that can account for fluorescence emission