Abstract A novel scheme to achieve a back reflector based on two-dimensional dielectric-metal graded metasurface is proposed, which presents high-efficiency over a broad range of incident solid angles and wavelengths. The remarkable performance of the back reflector is achieved by an effective optimization by searching the maximum reflection and the lowest deviation angle of solid space at a certain diffraction order. As a result, the optimized structure, working as a two-dimensional Littrow grating, is able to funnel the incident energy into the diffraction order (1,1) to reflect almost all (> 92%) the impinging light back to the source based on Huygens-Fresnel principle. The working wavelength of the back reflector can be tuned by simply adjusting the structural parameters of the graded metasurface.

中文翻译：

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高效、偏振无关的背反射器

摘要 提出了一种实现基于二维介电金属渐变超表面的背反射器的新方案，该方案在广泛的入射立体角和波长范围内均表现出高效率。背反射器的显着性能是通过在一定衍射级上搜索固体空间的最大反射和最小偏差角的有效优化来实现的。因此，作为二维 Littrow 光栅工作的优化结构能够将入射能量集中到衍射级 (1,1) 中，以将几乎所有 (> 92%) 的入射光反射回基于源的惠更斯-菲涅耳原理。后反射器的工作波长可以通过简单地调整渐变超表面的结构参数来调整。