Müller Paul, Schürmann Mirjam, Girardo Salvatore, Cojoc Gheorghe, Guck Jochen
Opt Express. 2018 Apr 16;26(8):10729-10743. doi: 10.1364/OE.26.010729.
Measuring the average refractive index (RI) of spherical objects, such as suspended cells, in quantitative phase imaging (QPI) requires a decoupling of RI and size from the QPI data. This has been commonly achieved by determining the object's radius with geometrical approaches, neglecting light-scattering. Here, we present a novel QPI fitting algorithm that reliably uncouples the RI using Mie theory and a semi-analytical, corrected Rytov approach. We assess the range of validity of this algorithm in silico and experimentally investigate various objects (oil and protein droplets, microgel beads, cells) and noise conditions. In addition, we provide important practical cues for the analysis of spherical objects in QPI.
在定量相位成像（QPI）中测量球形物体（如悬浮细胞）的平均折射率（RI），需要从QPI数据中解耦RI和尺寸。这通常是通过几何方法确定物体半径来实现的，而忽略了光散射。在这里，我们提出了一种新颖的QPI拟合算法，该算法使用米氏理论和半解析、修正的瑞托夫方法可靠地解耦RI。我们在计算机上评估了该算法的有效性范围，并通过实验研究了各种物体（油滴和蛋白质液滴、微凝胶珠、细胞）和噪声条件。此外，我们还为QPI中球形物体的分析提供了重要的实用提示。
