Point spread function in interferometric scattering microscopy (iSCAT). Part I: aberrations in defocusing and axial localization
Point spread function in interferometric scattering microscopy (iSCAT). Part I: aberrations in defocusing and axial localization
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DOI：
10.1364/oe.401374
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发表时间：
2020-08-31
期刊：
影响因子：
3.8
通讯作者：
Sandoghdar, Vahid
中科院分区：
文献类型：
--
作者：
Mahmoodabadi, Reza Gholami;Taylor, Richard W.;Sandoghdar, Vahid
干涉散射(ISCAT)显微镜是一种新兴的无标记技术，优化了对纳米物质的灵敏检测。以前的iSCAT研究已经用高斯强度分布来近似iSCAT中的点扩散函数。然而，最近为了跟踪纳米粒子在具有挑战性的散斑环境中和在更大的轴向范围内的迁移率的努力，需要对干涉点扩散函数(IPSF)进行定量描述。结合实验测量和严格的FDTD模拟，我们提出了一个稳健的IPSF矢量绕射模型。我们研究了不同成像场景下的IPSF，以了解实验构型引起的像差如何编码有关纳米颗粒的信息。我们表明，IPSF的横向形状可以通过与解析模型的拟合或无定标的无监督机器学习，在10微米量级的扩展轴向范围内实现纳米级的三维定位。我们的结果对复杂散射介质中的三维单粒子跟踪具有直接的意义。(C)OSA开放获取出版协议条款下的2020年美国光学学会
Interferometric scattering (iSCAT) microscopy is an emerging label-free technique optimized for the sensitive detection of nano-matter. Previous iSCAT studies have approximated the point spread function in iSCAT by a Gaussian intensity distribution. However, recent efforts to track the mobility of nanoparticles in challenging speckle environments and over extended axial ranges has necessitated a quantitative description of the interferometric point spread function (iPSF). We present a robust vectorial diffraction model for the iPSF in tandem with experimental measurements and rigorous FDTD simulations. We examine the iPSF under various imaging scenarios to understand how aberrations due to the experimental configuration encode information about the nanoparticle. We show that the lateral shape of the iPSF can be used to achieve nanometric three-dimensional localization over an extended axial range on the order of 10 mu m either by means of a fit to an analytical model or calibration-free unsupervised machine learning. Our results have immediate implications for three-dimensional single particle tracking in complex scattering media. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement