AVERAGE AND MOST-PROBABLE PHOTON PATHS IN RANDOM-MEDIA

Time-resolved experiments have revealed that, in contrast to the predi ctions of conventional diffusion theory, photons select certain curvil inear paths to travel between a source and a detector. Concepts of the average photon paths and Fermat paths are introduced on the basis of the non-Euclidean diffusion equation (NED) to explain experimental res ults. Comparison of the theory and the experiment demonstrates the pot ential of the NED to describe nondiffusive features of photon migratio n in the multiple-scattering regime. (C) 1997 Optical Society of Ameri ca.