Institute of Chemical Kinetics and Combustion, Novosibirsk 630090, Russia.
Cytometry A. 2011 Jul;79(7):570-9. doi: 10.1002/cyto.a.21074. Epub 2011 May 4.
We instrumentally, theoretically, and experimentally demonstrate a new approach for characterization of nonspherical individual particles from light scattering. Unlike the original optical scheme of the scanning flow cytometer that measures an angle-resolved scattering corresponding in general to S₁₁ element of the light-scattering matrix, the modernized instrument allows us to measure the polarized light-scattering profile of individual particles simultaneously. Theoretically, the polarized profile is expressed by the combination of a few light-scattering matrix elements. This approach supports us with additional independent data to characterize a particle with a complex shape and an internal structure. Applicability of the new method was demonstrated from analysis of polymer bispheres. The bisphere characteristics, sizes, and refractive indices of each sphere composing the bisphere were successfully retrieved from the solution of the inverse light-scattering problem. The solution provides determination of the Eulerian angles, which describe the orientation of the bispheres relative to the direction of the incident laser beam and detecting polarizer of the optical system. Both the ordinary and polarized profiles show a perfect agreement with T-matrix simulation resulting to 50-nm precision for sizing of bispheres.
我们从光散射的角度，在仪器、理论和实验上证明了一种用于描述非球形单个颗粒的新方法。与传统的扫描流动细胞仪的原始光学方案不同，该方案测量的是一般对应于光散射矩阵的 S₁₁元素的角度分辨散射，现代化仪器使我们能够同时测量单个颗粒的偏振光散射分布。从理论上讲，偏振分布由几个光散射矩阵元素的组合来表示。这种方法为我们提供了额外的独立数据，以描述具有复杂形状和内部结构的颗粒。从聚合物双球体的分析中证明了新方法的适用性。从反光散射问题的解中成功地提取了双球体的特征、尺寸和组成每个球体的折射率。该解决方案提供了对描述双球体相对于入射激光束和光学系统检偏器方向的取向的欧拉角的确定。普通和偏振分布都与 T 矩阵模拟完美吻合，双球体的尺寸精度达到 50nm。
