Sun W, Fu Q
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada.
Appl Opt. 2000 Oct 20;39(30):5569-78. doi: 10.1364/ao.39.005569.
The finite-difference time-domain (FDTD) technique is examined for its suitability for studying light scattering by highly refractive dielectric particles. It is found that, for particles with large complex refractive indices, the FDTD solution of light scattering is sensitive to the numerical treatments associated with the particle boundaries. Herein, appropriate treatments of the particle boundaries and related electric fields in the frequency domain are introduced and examined to improve the accuracy of the FDTD solutions. As a result, it is shown that, for a large complex refractive index of 7.1499 + 2.914i for particles with size parameters smaller than 6, the errors in extinction and absorption efficiencies from the FDTD method are generally less than approximately 4%. The errors in the scattering phase function are less than approximately 5%. We conclude that the present FDTD scheme with appropriate boundary treatments can provide a reliable solution for light scattering by nonspherical particles with large complex refractive indices.
研究了时域有限差分（FDTD）技术用于研究高折射率介电粒子光散射的适用性。结果发现，对于具有大复折射率的粒子，光散射的FDTD解对与粒子边界相关的数值处理很敏感。在此，引入并研究了频域中粒子边界和相关电场的适当处理方法，以提高FDTD解的精度。结果表明，对于尺寸参数小于6且复折射率为7.1499 + 2.914i的大粒子，FDTD方法在消光和吸收效率方面的误差通常小于约4%。散射相函数的误差小于约5%。我们得出结论，具有适当边界处理的当前FDTD方案可以为具有大复折射率的非球形粒子的光散射提供可靠的解。
