Abstract
Analytical expressions are derived for statistical measures of the penetration of radiation into two-layered tissues, based on a random-walk model of photon migration. In particular, we study the pigmented upper layer case, which is typical for most biological tissues, where the upper layer is the more absorptive one. Results are presented for the reemitted intensity profile, the averaged path length and for measures of the penetration depth of both re-emitted and internally absorbed radiation. These results are extremely important in medical applications for diagnostic and therapeutic purposes.