Predicting the optical response of macroscopic arrangements of individual scatterers is a computational challenge because the problem involves length scales across multiple orders of magnitude. We present a full-wave optical method to efficiently compute the scattering of light at objects that are arranged in biperiodic arrays. Multiple arrays or homogeneous thin films can be stacked to build up an entire multicomposite material in the third dimension. The scattering properties of the individual objects in each array are described by the T-matrix formalism. Therefore, arbitrarily shaped objects and even molecules can be the basic constituent of the arrays. Taking the T-matrix of the individual scatterer as the point of departure we can explain the optical properties of the bulk material from the scattering properties of its constituents. We use solutions of Maxwell’s equations with well-defined helicity. Therefore, chiral media are particularly easy to consider as materials for both scatterers and embedding media. We exemplify the efficiency of the algorithm with an exhaustive parametric study of anti-reflective coatings for solar cells made from cylinders with a high degree of helicity preservation. The example shows a speed-up factor of about 500 with respect to finite-element computations. A second example specifically exploits the use of helicity modes to investigate the enhancement of the circular dichroism signal in a chiral material.

中文翻译：

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基于 T 矩阵方法的双周期、分层结构的高效模拟

预测单个散射体宏观排列的光学响应是一项计算挑战，因为该问题涉及跨多个数量级的长度尺度。我们提出了一种全波光学方法来有效地计算排列在双周期阵列中的物体上的光散射。可以堆叠多个阵列或同质薄膜，以在三维空间中构建完整的复合材料。每个阵列中单个物体的散射特性由 T 矩阵形式描述。因此，任意形状的物体甚至分子都可以成为阵列的基本组成部分。以单个散射体的 T 矩阵为出发点，我们可以从其成分的散射特性来解释散装材料的光学特性。我们使用具有明确定义的螺旋度的麦克斯韦方程组的解。因此，手性介质特别容易被视为散射体和嵌入介质的材料。我们通过对由具有高度螺旋度保留的圆柱体制成的太阳能电池的抗反射涂层进行详尽的参数研究来举例说明该算法的效率。该示例显示了关于有限元计算的大约 500 的加速因子。第二个例子特别利用螺旋模式来研究手性材料中圆二色性信号的增强。我们通过对由具有高度螺旋度保留的圆柱体制成的太阳能电池的抗反射涂层进行详尽的参数研究来举例说明该算法的效率。该示例显示了关于有限元计算的大约 500 的加速因子。第二个例子特别利用螺旋模式来研究手性材料中圆二色性信号的增强。我们通过对由具有高度螺旋度保留的圆柱体制成的太阳能电池的抗反射涂层进行详尽的参数研究来举例说明该算法的效率。该示例显示了关于有限元计算的大约 500 的加速因子。第二个例子特别利用螺旋模式来研究手性材料中圆二色性信号的增强。