-
摘要生物医学光学已在快速、无创伤的医疗领域做出了举足轻重的贡献。本文采用蒙特卡罗模拟算法研究了混浊介质后向散射面上偏振特性的角向分布和空间分布规律。首先，在用Matlab实现相应算法的基础上，比较了相同的算法在Matlab，C++,Fortran三种不同的软件平台下的运行效率；同时结合蒙特卡罗算法的收敛性，在固定其他参数的基础上，讨论了欲使模拟达到收敛状态所需的最少光子数与组织层厚度、散射系数以及各向异性因子的的关系。在此基础上，设计了研究出射面上Mueller矩阵角向分布的程序，并得出了不同浓度的红细胞悬浮液后向和前向散射面上Mueller矩阵的角向分布，结合Mueller矩阵的极分解得出了保偏度、二向透过率系数以及相位延迟在后向和前向散射面上的角向分布规律；同时还结合实验结果分析了后向散射面上偏振特性的空间分布特征，采用格林变换将模拟的无限细光束照射下的结果转换成高斯分布的光束照射下的结果，发现与实验结果更为吻合。这些结果对研究浑浊介质的偏振特性有着重要的参考价值。9919
- 上一篇：多孔石墨烯衍生材料的第一性原理研究
- 下一篇：流体漩涡中小颗粒运动规律的实验研究
关键词：后向散射，偏振，蒙特卡罗模拟，Mueller矩阵，极分解
毕业设计说明书（论文）外文摘要
Title Polarization studies for spatial and angular distribution on
backscattering surface of turbid media
Abstract:
Biomedical optics has made great contribution to the rapid, non-invasive medical field. In this paper, Monte Carlo simulation algorithm was used to study the law for angular distribution and spatial distribution of the polarization properties on the backscattering surface of turbid media. First, based on the corresponding Matlab algorithm, We compared the operating efficiency of the same algorithms with three different software languages, which are Matlab, C++, and Fortran. And considering the convergence of Monte Carlo algorithm, We discussed the relationship between the minimum number of photons which makes simulation convergent and tissue thickness, scattering coefficient and anisotropy factor on the basis of the other fixed parameters. Then we developed the program to simulate angular distribution of Mueller matrix on backscattering surface and forwardscattering surface of erythrocyte suspensions with different concentrations. The polar decomposition algorithm is used to extract the depolarization index, the diattenuation index and the retardance index. At the same time, we analysis the polarization properties of the spacial distribution on the backscattering surface. Adopting the Green Transformation, we converted the result of infinite narrow beam irradiation into the result of the beam with Gaussian distribution which is in qualitative agreement with experimental result. These results are valuable on the study of polarization characteristics of turbid media.
Keywords：backscattered light, polarization, Monte Carlo Simulation，Mueller matrix, polar decomposition
目 录
1 绪论 1
1.1 研究意义 1
1.2 研究进展 1
1.3 本文主要工作 2
2 光散射偏振特性的理论基础 3
2.1 光散射偏振特性概述 3
2.1.1 偏振光及Stokes 矢量 3
2.1.2 Mueller矩阵 4
2.2 Mie散射理论概述 4
2.2.1 Mie散射理论 4