A material is optically characterized at the wavelengths of interest by microscopic absorption and scattering coefficients,k and s, and the anisotropy, g, or average cosine of the scattering angle. The light flux in a highly scattering medium can be calculated with the photon diffusion equation which is derived from radiative transfer theory. The distribution of light throughout the material as well as the diffuse reflectance and transmittance, R and T, of a material can be determined from k, s and g with mathematical tissue optics theories or with a Monte Carlo computer simulation. The propagation of light through tissue has been successfully modeled with Monte Carlo simulation. Light that emerges from the front or rear surface is counted as reflection or transmission.
Absorbed light is counted in a two or three-dimensional array to allow for flux density output.
Monte Carlo Scattering Program V1.0 is the program I wrote that allows one to see light transport in three dimensions through a user defined tissue sample. This page originally written by Dr. Linda Jones from the College of Charleston's Physics department.