  We develop a method based on Markov chains to model fluorescence, absorption,
and scattering in nanophotonic systems. We show that the method reproduces
Beer-Lambert's Law and Kirchhoff's Law, but also can be used to analyze
deviations from these laws when some of their assumptions are violated. We show
how to use the method to analyze a luminescent solar concentrator (LSC) based
on semiconductor nanocrystals.
