Abstract

The validity of photon diffusion for infinite, homogeneous media is investigated by Monte Carlo methods. The photon diffusion coefficient (D) is found to be independent of absorption, i.e $D=\frac{v}{3{\mu }_s^{\text{'}}}$. The validity of the diffusion approximation for heterogeneous media with spherical tumors of order 1/μ_s′ around the source is investigated by comparing diffusion theory with Monte Carlo simulations for various parameters.

© 1996 Optical Society of America