光学学报, 2016, 36 (12): 1226001, 网络出版: 2016-12-14
米散射介质退偏特性的表征与计算方法
Characterization and Calculation Methods of Depolarization Properties of Mie Scatterers
物理光学 组织光学 保偏系数 米勒矩阵分解 米散射介质 米勒相关矩阵 熵 physical optics tissue optics polarization-maintaining index Mueller matrix Mie scatterers Mueller coherence matrix entropy
摘要
对比描述米散射介质退偏特性的米勒矩阵分解法和米勒相关矩阵法, 讨论了完备的退偏特性描述参数。发现退偏介质在不含其他偏振特性时, 分解法和相关矩阵法得到的保偏系数与标准值的差异会随着介质主轴方向上的退偏各向异性程度增大而增大, 此差异最大时分别为0.16和0.07, 相对差值分别为33%和15%。由于米散射介质表现出退偏各向异性特征, 发现除了可用退偏各向异性系数表征此特性外, 保偏系数-熵图也可定性地反映介质的退偏各向异性程度。而当介质表现出其他偏振特性, 如双折射和旋光等效应时线性退偏会表现出各向异性特征, 此时还需引入线性退偏各向异性系数才可完备地表征米散射介质的退偏特性。
Abstract
Mueller matrix decomposition method and Mueller coherence matrix method for the complete depolarization characteristics of Mie scatterers are compared. The parameters of the depolarization characteristics are discussed. It is found that when the depolarizing medium doesn’t contain other polarization characteristics, the difference between the general polarization-maintaining indexes calculated by decomposition method and coherence matrix, and the standard value will increase with the deviation degree of anisotropy coefficient of depolarization along the medium’s principal axis. The maximum divergences are 0.16 and 0.07 and the relative divergences are 33% and 15% respectively. Because of the depolarization anisotropy in Mie scatterers, the polarization-maintaining index-entropy chart can also be used to denote the depolarization anisotropy qualitatively, as well as the anisotropy coefficient of depolarization. When the Mie scatterers show other polarization properties, for example the birefringence and the optical rotation, the linear depolarization will show the anisotropic property. At the moment, the linear depolarization anisotropy factor should be introduced to completely depict the depolarization characteristics of Mie scatters.
王雪珍, 来建成, 李振华. 米散射介质退偏特性的表征与计算方法[J]. 光学学报, 2016, 36(12): 1226001. Wang Xuezhen, Lai Jiancheng, Li Zhenhua. Characterization and Calculation Methods of Depolarization Properties of Mie Scatterers[J]. Acta Optica Sinica, 2016, 36(12): 1226001.