Discrete dipole approximation method for electromagnetic scattering by particles in an absorbing host medium
Discrete dipole approximation method for electromagnetic scattering by particles in an absorbing host medium
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吸收主体介质中粒子电磁散射的离散偶极近似方法
DOI：
10.1364/oe.418467
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发表时间：
2021-03-01
期刊：
影响因子：
3.8
通讯作者：
Liu, Linhua
中科院分区：
文献类型：
--
作者：
Dong, Jian;Zhang, Wenjie;Liu, Linhua
颗粒在吸收介质中的电磁散射是实际应用中经常遇到的问题，这使得传统的电磁散射理论备受争议，大多数电磁散射理论方法都不适用。文献中的相关工作大多局限于球形粒子。在这项工作中，我们发展了离散偶极子近似(DDA)方法来计算浸没在吸收主体介质中的任意粒子的电磁散射。我们详细阐述了如何利用DDA来计算近场和远场散射量。通过与精确Mie理论计算的球形粒子的表观散射量和固有散射量的比较，验证了DDA的准确性。然后用DDA研究了非吸收球体在吸收宿主介质中对电磁波的消光。我们发现，入射方向延长的粒子更有可能产生负的表观消光，近场电场分布也支持这一点。我们发展的DDA方法将为研究吸收宿主介质中颗粒的电磁散射提供一种实用而灵活的方法。(C)OSA开放获取出版协议条款下的2021年美国光学学会
Electromagnetic (EM) scattering by particles in an absorbing host medium is frequently encountered in practical applications, which makes the conventional EM scattering theory controversial and most of the theoretical methods for EM scattering inapplicable. Most of the relevant works in literature are confined to spherical particles. In this work, we develop the discrete dipole approximation (DDA) method for EM scattering by an arbitrary particle immersed in an absorbing host medium. We elaborate how the near- and far-field scattering quantities can be calculated by DDA. The accuracy of DDA is validated by comparison with the apparent and inherent scattering quantities of spherical particles computed by exact Mie theory. Then EM extinction by non-absorbing spheroids in absorbing host medium is studied by DDA. We find that particles that are prolonged in the incident direction are more likely to produce a negative apparent extinction, which is also supported by the near-field electric field distribution. The DDA method we develop will be useful and flexible in the study of EM scattering by particles in absorbing host medium. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement