Accurate and fast modeling of scattering from random arrays of nanoparticles using the discrete dipole approximation and angular spectrum method
Accurate and fast modeling of scattering from random arrays of nanoparticles using the discrete dipole approximation and angular spectrum method
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DOI：
10.1364/oe.431754
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发表时间：
2021-07-05
期刊：
影响因子：
3.8
通讯作者：
McLeod, Euan
中科院分区：
文献类型：
--
作者：
Baker, Maryam;Liu, Weilin;McLeod, Euan
无透镜显微镜可以利用全息重建技术，从数字记录的未扰动平面波和物体散射波的叠加中恢复物体的图像。图像重建通常依赖于标量角谱方法（ASM）。虽然速度很快，但标量ASM对于纳米级物体可能是不准确的，因为标量近似，或者更一般地说，因为它只模拟场传播而不是光-物质相互作用，包括粒子间耦合。在这里，我们评估的准确性结合三种不同的光-物质相互作用模型计算的远场光散射的随机阵列的黄金和聚苯乙烯纳米粒子的标量ASM。在这三种模型中偶极匹配传输模型、光程长度模型和二进制振幅模型，我们发现哪种模型最准确取决于纳米颗粒材料和堆积密度。对于任何堆积密度的聚苯乙烯颗粒，总是有至少一个模型的误差低于20%，而对于具有40%或50%表面覆盖度的金纳米颗粒，没有模型可以提供优于30%的误差。ASM误差的确定相比，离散偶极子近似模型，这是更有效的计算比其他全波建模技术。ASM何时以及如何失败的知识可以作为无透镜重建中提高分辨率的第一步，也可以应用于其他随机纳米颗粒阵列应用，例如基于透镜的超分辨率成像，亚衍射光束聚焦和生物分子传感。(C)根据OSA开放获取出版协议的条款，2021年美国光学学会
Lens-free microscopes can utilize holographic reconstruction techniques to recover the image of an object from the digitally recorded superposition of an unperturbed plane wave and a wave scattered by the object. Image reconstruction most commonly relies on the scalar angular spectrum method (ASM). While fast, the scalar ASM can be inaccurate for nanoscale objects, either because of the scalar approximation, or more generally, because it only models field propagation and not light-matter interaction, including inter-particle coupling. Here we evaluate the accuracy of the scalar ASM when combined with three different light-matter interaction models for computing the far-field light scattered by random arrays of gold and polystyrene nanoparticles. Among the three models-a dipole-matched transmission model, an optical path length model, and a binary amplitude model-we find that which model is most accurate depends on the nanoparticle material and packing density. For polystyrene particles at any packing density, there is always at least one model with error below 20%, while for gold nanoparticles with 40% or 50% surface coverage, there are no models that can provide errors better than 30%. The ASM error is determined in comparison to a discrete dipole approximation model, which is more computationally efficient than other full-wave modeling techniques. The knowledge of when and how the ASM fails can serve as a first step toward improved resolution in lens-free reconstruction and can also be applied to other random nanoparticle array applications such as lens-based super-resolution imaging, sub-diffraction beam focusing, and biomolecular sensing. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement