【作者】 袁兴起；

【导师】 陈延如； 赵琦；

【作者基本信息】 南京理工大学 ， 光学工程， 2007， 博士

【摘要】 随机分布群粒子入射激光复合散射特性研究在现代科学和工程中有着广泛的应用。本文研究了群体粒子场光学侧向散射特性及其数学模型描述。在用相同波长线偏振和圆偏振两种偏振状态的He-Ne激光束入射到一随机分布群粒子场以产生侧向散射光,并测得散射偏振光强的实验基础上,分析得到了群体粒子场激光侧向散射的特性规律,建立了Muller-Stokes算法数学模型来描述其散射特征,并验证了利用该模型得到的群体粒子场激光侧向散射规律与实验结果是相吻合的。围绕着群体粒子场侧向散射光的性质分析,本文开展了一系列研究:设计了用于研究群体粒子场激光侧向散射特性的实验系统及实验方法;从实验上测量了不同偏振态入射光照射下不同直径粒子在不同体积分数浓度时侧向散射光的不同偏振态光强,通过相应的处理获得了散射光强度及其偏振度相对散射角的分布图样,分析得到了散射光强及偏振度相对散射角的变化规律;建立了多粒子散射的Muller-Stokes矩阵描述数学模型,利用模型阐明了群体粒子侧向散射的多种性质特征,验证了该模型得到的群体粒子场激光侧向散射规律与实验结果是相吻合的,从而用Muller-Stokes矩阵实现了对群粒子侧向散射现象的简明化数学表示。用此算法对实验得到的数据进行计算得到的结果表明:散射光强呈轴对称分布;散射光偏振特性的变化及用于表示各种特性的矩阵的元素主要决定于散射粒子的大小;另外,群粒子场侧向散射系数亦随粒子直径的变化而变化明显。这种Muller-Stokes算法把散射场模拟成一个光学系统,对入射偏振光束的散射效果给以简明的描述,给出了垂直于入射光方向的平面上各种散射特征的信息。本文对群粒子场激光侧向散射性质规律的研究结果及建立的群粒子散射数学模型在光散射研究领域尤其是多粒子激光散射的理论及应用方面有一定的价值,在激光散射技术具体应用方面如对糖尿病人血糖浓度的测量,对导弹或火箭羽烟的成分、浓度及其随时间空间的变化情况的测定,对沙尘暴天气进行早期的判断等等也是很有意义的。更多还原

【Abstract】 The researches on the properties of a laser radiation side-scattered by the multiple particles distributed randomly have extensive applications in modern science and engineering. The light scattering properties of the multiple particles field and its mathematical model description are studied in this dissertation. The linearly polarized and circularly polarized He-Ne laser radiation having the same wave-length incidence the field of multiple particles distributed randomly to create side-scattering light and on the basis of the experiment of measuring the scattering light intensities, the properties of scattered radiation are acquired, and the Muller-Stokes matrix mathematical model is developed to descript the properties. The properties of the radiation side-scattered by the multiple particles distributed randomly deducing from the model are in accordance with the experimental results.In order to realize the subjects, a series of research have been done as below: The experiment system used to study the properties of the side-scattered radiation in the multiple particles field is designed; the side-scattered radiation intensities of different polarizations are measured in experiments when using different polarization light incidence different volume concentration liquids consisted of particles of different diameters, the distributions of the intensities and the polarizations of the side-scattered radiation versus scattering angles are acquired and its variation regulations are studied; the mathematical model of the Muller-Stokes matrix to descript the multiple scattering is developed , many characteristics of the side-scattering radiation of the multiple particles field are revealed by the model, and the properties of the side-scattered radiation deducing from the model are in accordance with the experimental results, and then the simplified mathematical representation of the particle scattering is realized by using the Muller-Stokes matrix. By calculating the experimental data using this algorithm, the results show that the intensity of scattered radiation is axial symmetric, and the variations of the characteristics of scattered radiation and the matrix elements representing the scattering characteristics depend primarily upon particle size; in addition, the fraction of the scattering varies dramatically with particle diameters. This Muller-Stokes matrix algorithm regards the scattering field as an optical system, giving the simplified description of the scattering effect of the polarized incidence radiation, showing the information of the scattering characteristics in the plane perpendicular to the direction of the incidence light.The researches of the properties of the side-scattered radiation in the multiple particles field and the developed mathematical model of the multiple scattering have important reference value either for studying radiation scattering especially studying the theories and applications of multiple particles’ laser radiation scattering or for practically applying the laser scattering technologies such as the measurement of the blood sugar concentration of the diabetics, the measurement of the missle or rocket plumes compositions, concentrations and its varying corresponding to time or space, and the forecast of the sandstorm weather, etc.更多还原