Photonic funnels, microscale conical waveguides that have been recently realized in the mid-IR spectral range with the help of an all-semiconductor designer metal material platform, are promising devices for efficient coupling of light between the nanoscales and macroscales. Previous analyses of photonic funnels have focused on structures with highly conductive claddings. Here, we analyze the performance of funnels with and without cladding, as a function of material properties, operating wavelength, and geometry. We demonstrate that bare (cladding-free) funnels enable orders-of-magnitude higher enhancement of local intensity than their clad counterparts, with virtually no loss of confinement, and relate this phenomenon to anomalous reflection of light at the anisotropic material–air interface. Intensity enhancement of the order of 25, with confinement of light to wavelength/20 scale, is demonstrated. Efficient extraction of light from nanoscale areas is predicted.

中文翻译：

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利用光子漏斗进行高效亚波长光聚集和提取的反常反射


光子漏斗，即最近在全半导体设计师金属材料平台的帮助下在中红外光谱范围内实现的微型锥形波导，是在纳米尺度和宏观尺度之间有效耦合光的有前途的器件。先前对光子漏斗的分析主要集中在具有高导电包层的结构上。在这里，我们分析了有或没有包层的漏斗的性能，作为材料特性、工作波长和几何形状的函数。我们证明，裸露（无包层）漏斗能够比包层漏斗提高几个数量级的局部强度，几乎没有限制损失，并将这种现象与各向异性材料-空气界面处的反常光反射联系起来。证明了将光限制在波长/20 范围内，强度增强了 25 量级。预计可以从纳米级区域有效提取光。