Measurement Of The Diffuse Backscattering Mueller Matrix Of Turbid Medium

Several studies suggest that relevant information can be obtained from measurements of the spatially dependent response of a medium to a polarized point source. The Mueller matrix operator can completely determine the transformation of an arbitrary incident polarization state. In the case of diffusely backscattered light generated by point illumination, each matrix element is represented by a two-dimensional surface map. In the paper, A polarization-imaging system was developed to measure the two-dimensional diffuse backscattering Mueller matrix of turbid medium. The theoretical part of this paper focuses on the principle of the measurement of the two-dimensional diffuse backscattering Mueller matrix of turbid medium. In the part, we employed Stokes–Mueller formalism is to describe scattering events. The mathematical deduction of the theory about the system are presented in the condition of perfect optics. The poincarésphere with unit radius was introduced to describe the physical meanings of the measuring result. In this thesis, we proved that a total of 16 intensity measurements suffice to obtain Mueller matrix of the simple. In this thesis, we designed and accomplished a set of measuring system for diffuse backscattering Mueller matrix of turbid medium based on polarization-imaging technology. In the system, a polarized, collimated laser beam is focused to a small point on the medium, and the multiply scattered, diffusely backreflected light around this point is recorded with a CCD camera. Using a collinear or crossed analyzer in front of the camera, one obtains two-dimensional, polarization-dependent, surface intensity maps. In addition, we calibrated the system. And then, the specular reflecting Mueller matrix of the non-polarizing beamsplitter and the two-dimensional diffuse backscattering Mueller matrix of a 1.5% Intralipid solution were measured by the system. The result of the experiments confirms that the system can avoid the specular reflectance of the sample and exactly measure the Mueller matrix of the sample. The system can be use to measure the diffuse backscattering Mueller matrix of tissue.