ABSTRACT
Glossary of Sym bols............................................................................ 68
References............................................. ............................................... 69
1 Introduction
In this chapter we discuss the propagation of light in multiple scattering media, i.e. in materials which appear white or turbid. These materials probably contribute the most common ‘aggregate state’ in nature, ex amples ranging from paint, paper, bio-materials, milk, rock to clouds. In multiple scattering samples, the incoming light is scattered successively numerous times, thereby rapidly losing the memory of the incident dir ection. After some scattering events, the propagation is a diffusion pro cess. Consequently, the light emitted from the turbid media is also diffuse, the intensity varying only weakly with respect to the angle of observation (see Fig. 2). The diffuse propagation of light, through a slab of a turbid media, for example is well understood since the beginning of the 19th century and is known as the Schwarzschild-Milne problem [l]-[3].
