Deducing effective light transport parameters in optically thin systems

We present an extensive Monte Carlo study on light transport in optically thin slabs, addressing both axial and transverse propagation. We systematically characterize diffusive transport in this intermediate scattering regime, notably in terms of the spatial variance of the transmitted/reflected profile. Focusing on late, multiply scattered light, we test the validity of the prediction cast by diffusion theory that the spatial variance should grow independently of absorption and, to a first approximation, of the sample thickness and refractive index contrast. Based on a large set of simulated data, we build a freely available look-up table routine enabling reliable and precise determination of the microscopic transport parameters starting from robust observables which are independent from absolute intensity measurements. We also present the Monte Carlo software package that was developed for the purpose of this study.