论文标题
使用光散射模式的相光谱检索单个球体的折射率
Retrieving refractive index of single spheres using the phase spectrum of light-scattering pattern
论文作者
论文摘要
我们分析了在温格尔 - 克拉默斯 - 布里林（WKB）近似框架中球形角度分辨光散射模式（LSP）的复杂傅立叶光谱的行为。具体而言，我们表明，振幅光谱的主要峰值的相值几乎四边形取决于粒子折射率，这是通过使用WKB近似和严格的Lorenz-Mie理论的数值模拟来证实的。基于这些结果，我们构建了一种使用主要峰位置和相值来表征聚苯乙烯珠的方法。我们在嘈杂的合成LSP和用扫描流式细胞仪测量的实际数据上测试了该方法。在这两种情况下，光谱方法与参考非线性回归一致。前一种方法会导致检索到的粒子特性的可比误差，但比后者快300倍。光谱方法的唯一缺点是粒子特性的操作范围有限，由于相位包裹，需要先验设置为先验。因此，其主要应用利基是对特征变化范围较小的球体的快速而精确的表征。
We analyzed the behavior of the complex Fourier spectrum of the angle-resolved light scattering pattern (LSP) of a sphere in the framework of the Wentzel-Kramers-Brillouin (WKB) approximation. Specifically, we showed that the phase value at the main peak of the amplitude spectrum almost quadratically depends on the particle refractive index, which was confirmed by numerical simulations using both the WKB approximation and the rigorous Lorenz-Mie theory. Based on these results, we constructed a method for characterizing polystyrene beads using the main peak position and the phase value at this point. We tested the method both on noisy synthetic LSPs and on the real data measured with the scanning flow cytometer. In both cases, the spectral method was consistent with the reference non-linear regression one. The former method leads to comparable errors in retrieved particle characteristics but is 300 times faster than the latter one. The only drawback of the spectral method is a limited operational range of particle characteristics that need to be set a priori due to phase wrapping. Thus, its main application niche is fast and precise characterization of spheres with small variation range of characteristics.
