Luminescence of turbid materials: a theoretical model and its comparison with experiment.

A four-flux model describing the absorption and emission of radiation in turbid materials has been developed. Several limit cases were considered. In order to test the model, measurements of absorption, emission, and scattering were performed on samples of luminescent polymer in both transparent and turbid states. The directly measured (in transparent state) and computed (from the measurements in turbid state) spectra and quantum yields were compared. The dependence of ratios of computed values to true values of these parameters on the absorption to scattering ratio was empirically evaluated.