|ECE532 Biomedical Optics
© 1998 Steven L. Jacques, Scott A. Prahl
Oregon Graduate Institute
We are already familiar with the simple Beer's Law description of photon survival in an absorbing medium:
In a scattering medium, the photon's path is not a straight line, but Beer's law still holds. Regardless of how tortuous the path, the pathlength is given by:
At any point in time, one can calculate the probability of photon survival by exp(-µaL) = exp(-µact).