INVERSE HYBRID TECHNIQUE FOR DETERMINING THE OPTICAL-PROPERTIES OF TURBID MEDIA FROM INTEGRATING-SPHERE MEASUREMENTS

We have combined the Monte Carlo method with the small-angle approxima tion of the radiative transfer theory to derive the optical properties (the absorption coefficient, the scattering coefficient, and the anis otropy factor) of turbid materials from integrating-sphere measurement s (the total transmittance and the diffuse reflectance) and the collim ated transmittance. Unlike one-dimensional models, the technique accou nts for the side losses of light at the edges of the sample. in additi on, it enables the correction of the measured collimated signal for th e contribution of multiply scattered light. On the other hand, the hyb rid technique allows a significant reduction in calculation time compa red with inverse methods based on a pure Monte Carlo technique. Numeri cal tests and experimental results from a phantom material (milk) as w ell as samples of biological tissue (porcine myocardium) confirmed the feasibility of applying this technique to the determination of the op tical properties of turbid media. (C) 1996 Optical Society of America