Abstract

It is shown that the intensity of light reflected from plane-parallel turbid media is anisotropic in all situations encountered in practice. The anisotropy, in the form of higher intensity at large polar angles, increases when the amount of near-surface bulk scattering is increased, which dominates in optically thin and highly absorbing media. The only situation with isotropic intensity is when a non-absorbing infinitely thick medium is illuminated diffusely. This is the only case where the Kubelka–Munk model gives exact results and there exists an exact translation between Kubelka–Munk and general radiative transfer. This also means that a bulk scattering perfect diffusor does not exist. Angle-resolved models are thus crucial for a correct understanding of light scattering in turbid media. The results are derived using simulations and analytical calculations. It is also shown that there exists an optimal angle for directional detection that minimizes the error introduced when using the Kubelka–Munk model to interpret reflectance measurements with diffuse illumination.

© 2010 Optical Society of America

Anisotropic reflectance from turbid media. II. Measurements

Magnus Neuman and Per Edström
J. Opt. Soc. Am. A 27(5) 1040-1045 (2010)

Hybrid model of Monte Carlo simulation and diffusion theory for light reflectance by turbid media

Lihong Wang and Steven L. Jacques
J. Opt. Soc. Am. A 10(8) 1746-1752 (1993)

Multiple path analysis of reflectance from turbid media

Geoffrey L. Rogers
J. Opt. Soc. Am. A 25(11) 2879-2883 (2008)

Examination of the revised Kubelka-Munk theory: considerations of modeling strategies

Per Edström
J. Opt. Soc. Am. A 24(2) 548-556 (2007)

Point spreading in turbid media with anisotropic single scattering

Magnus Neuman, Ludovic G. Coppel, and Per Edström
Opt. Express 19(3) 1915-1920 (2011)