Karagounis G, De Zutter D, Vande Ginste D
Opt Express. 2013 Dec 16;21(25):30379-91. doi: 10.1364/OE.21.030379.
In this paper, a two-dimensional high-frequency formalism is presented which describes the diffraction of arbitrary wavefronts incident on edges of an otherwise smooth surface. The diffracted field in all points of a predefined region of interest is expressed in terms of the generalized Huygens representation of the incident field and a limited set of translation coefficients that take into account the arbitrary nature of the incident wavefront and its diffraction. The method is based on the Uniform Theory of Diffraction (UTD) and can therefore be utilized for every canonical problem for which the UTD diffraction coefficient is known. Moreover, the proposed technique is easy to implement as only standard Fast Fourier Transform (FFT) routines are required. The technique's validity is confirmed both theoretically and numerically. It is shown that for fields emitted by a discrete line source and diffracted by a perfectly conducting wedge, the method is in excellent agreement with the analytic solution over the entire simulation domain, including regions near shadow and reflection boundaries. As an application example, the diffraction in the presence of a perfectly conducting wedge illuminated by a complex light source is analyzed, demonstrating the appositeness of the method.
本文提出了一种二维高频形式体系，用于描述入射到光滑表面边缘的任意波前的衍射。在预定义感兴趣区域的所有点处的衍射场，是根据入射场的广义惠更斯表示以及一组有限的平移系数来表示的，这些系数考虑了入射波前的任意性质及其衍射。该方法基于一致性绕射理论（UTD），因此可用于任何已知UTD衍射系数的典型问题。此外，所提出的技术易于实现，因为只需要标准的快速傅里叶变换（FFT）例程。该技术的有效性在理论和数值上均得到了证实。结果表明，对于由离散线源发射并由理想导电楔衍射的场，该方法在整个模拟域内，包括阴影和反射边界附近的区域，都与解析解非常吻合。作为一个应用示例，分析了在由复杂光源照射的理想导电楔存在的情况下的衍射，证明了该方法的适用性。
