Goray Leonid I, Schmidt Gunther
I.I.G., Inc., P.O. Box 131611, Staten Island, New York 10313, USA.
J Opt Soc Am A Opt Image Sci Vis. 2010 Mar 1;27(3):585-97. doi: 10.1364/JOSAA.27.000585.
Off-plane scattering of time-harmonic plane waves by a plane diffraction grating with arbitrary conductivity and general surface profile is considered in a rigorous electromagnetic formulation. Integral equations for conical diffraction are obtained involving, besides the boundary integrals of the single and double layer potentials, singular integrals, the tangential derivative of single-layer potentials. We derive an explicit formula for the calculation of the absorption in conical diffraction. Some rules that are expedient for the numerical implementation of the theory are presented. The efficiencies and polarization angles compared with those obtained by Lifeng Li for transmission and reflection gratings are in a good agreement. The code developed and tested is found to be accurate and efficient for solving off-plane diffraction problems including high-conductive gratings, surfaces with edges, real profiles, and gratings working at short wavelengths.
在严格的电磁学公式中，考虑了具有任意电导率和一般表面轮廓的平面衍射光栅对时谐平面波的离面散射。得到了锥形衍射的积分方程，除了单层和双层势的边界积分外，还涉及奇异积分和单层势的切向导数。我们推导了一个用于计算锥形衍射中吸收的显式公式。给出了一些便于该理论数值实现的规则。与李立峰所得到的透射和反射光栅的效率及偏振角相比，结果吻合良好。所开发和测试的代码对于解决包括高导电光栅、带边缘表面、实际轮廓以及工作在短波长的光栅在内的离面衍射问题是准确且高效的。
