Halimeh Jad C, Schmied Roman, Wegener Martin
Physics Department, Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität München, München, Germany.
Opt Express. 2011 Mar 28;19(7):6078-92. doi: 10.1364/OE.19.006078.
Grating cloaks are a variation of dielectric carpet (or ground-plane) cloaks. The latter were introduced by Li and Pendry. In contrast to the numerical work involved in the quasi-conformal carpet cloak, the refractive-index profile of a conformal grating cloak follows a closed and exact analytical form. We have previously mentioned that finite-size conformal grating cloaks may exhibit better cloaking than usual finite-size carpet cloaks. In this paper, we directly visualize their performance using photorealistic ray-tracing simulations. We employ a Newtonian approach that is advantageous compared to conventional ray tracing based on Snell's law. Furthermore, we quantify the achieved cloaking quality by computing the cross-correlations of rendered images. The cross-correlations for the grating cloak are much closer to 100% (i.e., ideal) than those for the Gaussian carpet cloak.
光栅隐身衣是介电地毯（或地平面）隐身衣的一种变体。后者由李和彭德里提出。与准共形地毯隐身衣所涉及的数值工作不同，共形光栅隐身衣的折射率分布遵循一种封闭且精确的解析形式。我们之前提到过，有限尺寸的共形光栅隐身衣可能比普通的有限尺寸地毯隐身衣表现出更好的隐身效果。在本文中，我们使用逼真的光线追踪模拟直接可视化它们的性能。我们采用一种牛顿方法，与基于斯涅尔定律的传统光线追踪相比具有优势。此外，我们通过计算渲染图像的互相关来量化所实现的隐身质量。光栅隐身衣的互相关比高斯地毯隐身衣的互相关更接近100%（即理想状态）。
