Ray A K, Nandakumar R
Appl Opt. 1995 Nov 20;34(33):7759-70. doi: 10.1364/AO.34.007759.
A technique for determining the size and wavelength-dependent refractive indices of a droplet coated with a thin layer is presented. The existence of a layer on the droplet is identified by a procedure that involves separate alignments of independently measured TE- and TM-mode resonances with computed homogeneous-sphere resonances. The procedure also yields the mode and the order numbers associated with the measured resonances. The observed resonances are then aligned with layered-sphere resonances of the same mode and order numbers to determine the core radius, layer thickness, and constants of core and shell dispersion formulas that minimize the difference between the observed and the calculated positions of resonances. The technique has been tested with synthetic data with various levels of random errors as well as with experimental data from two droplets under identical conditions. The results show that the core radius, layer thickness, and core and layer refractive indices can be determined with relative errors of 3.5 × 10(-4), 4.5 × 10(-2), 2.3 × 10(-4), and 4.4 × 10(-3), respectively, with the technique.
本文提出了一种用于确定涂有薄层的液滴的尺寸和波长相关折射率的技术。通过一种程序来识别液滴上存在的层，该程序涉及将独立测量的TE和TM模式共振与计算出的均匀球体共振进行单独对齐。该程序还会得出与测量共振相关的模式和阶数。然后将观察到的共振与相同模式和阶数的分层球体共振进行对齐，以确定核心半径、层厚度以及核心和壳层色散公式的常数，从而使观察到的和计算出的共振位置之间的差异最小化。该技术已用具有各种随机误差水平的合成数据以及在相同条件下来自两个液滴的实验数据进行了测试。结果表明，使用该技术可以分别以3.5×10⁻⁴、4.5×10⁻²、2.3×10⁻⁴和4.4×10⁻³的相对误差确定核心半径、层厚度以及核心和层的折射率。
