Light Propagation in Highly Scattering Turbid Media: Concepts, Techniques, and Biomedical Applications

This chapter provides an overview of the physics of light propagation in highly scattering turbid media, such as biological tissues, the techniques that enable using light emergent from those media for gaining information about the media interior, and their potential application in biomedical imaging. The interaction of light with a scattering medium, characteristics of the transmitted light, key parameters that characterize the light emergent from the medium, and light gating methods that reduce the deleterious effect of multiple scattered light and help clear up images is presented in the chapter. Over the years, several schemes have evolved to sort out the direct image-bearing ballistic and snake photons from the multiple-scattered diffuse photons. These schemes exploit one or more of the changes that scattering induces on the characteristics such as directionality, polarization, absorption, coherence, and temporal duration of the incident light.