Light Diffuse Reflectance Properties From The Surface Of Scattering Media With Complicated Structures

This thesis is devoted to the light diffuse reflectance properties from the surfaces of scattering media with complicated structures (such as biological tissues), theoretically and experimentally.The background and the basic scheme of Monte Carlo method, also the necessity and the significance of its application in tissue optics, are presented firstly. Some main developments made recently are reviewed. Then, a common misinterpret included in the "Principle of Similarity" is pointed out and corrected.Monte Carlo method is also used to analyze the spatial distribution of diffuse reflectance light from scattering media irradiated by several common beams of light. A new conclusion that the surface of scattering media (or biological tissue) is not the ideal Lambertian diffuser is obtained. The results above have been confirmed by experiments. Therefore, exact method to determine diffuse reflectance coefficient of tissue should be a spatial integral to diffuse reflectance light from the surface of tissue.Using the Mueller matrix, the polarization properties of diffusereflectance light from the surface of scattering media are studied preliminary. Depolarization is calculated; also, the spatial distribution of depolarization and the relation of depolarization and optical properties of scattering media are analyzed.In addition to Monte Carlo simulation, the experimental methods are used to study how the diffuse reflectance light from the surface of scattering media with complicated structures (such as two-layered) respond while the optical properties of the inner layer change. Some significant results have been obtained that optical properties' micro-change of the inner layer which has low optical properties will influence on the diffuse reflectance light from the surface greatly. It is promising to play a role in the monitoring to glucose concentration and blood quantity...