Jeon Jiyeon, Bhattarai Khagendra, Kim Deok-Kee, Kim Jun Oh, Urbas Augustine, Lee Sang Jun, Ku Zahyun, Zhou Jiangfeng
Division of Convergence Technology, Korea Research Institute of Standards and Science, Daejeon, 305-340, Korea.
Department of Electrical Engineering, Sejong University, Seoul 143-747, Korea.
Sci Rep. 2016 Nov 2;6:36190. doi: 10.1038/srep36190.
Over the years, there has been increasing interest in the integration of metal hole array (MHA) with optoelectronic devices, as a result of enhanced coupling of incident light into the active layer of devices via surface plasmon polariton (SPP) resonances. However, not all incident light contributes to the SPP resonances due to significant reflection loss at the interface between incident medium and MHA. Conventional thin-film antireflection (AR) coating typically does not work well due to non-existing material satisfying the AR condition with strong dispersion of MHA's effective impedances. We demonstrate a single-layer metasurface AR coating that completely eliminates the refection and significantly increases the transmission at the SPP resonances. Operating at off-resonance wavelengths, the metasurface exhibits extremely low loss and does not show resonant coupling with the MHA layer. The SPP resonance wavelengths of MHA layer are unaffected whereas the surface wave is significantly increased, thereby paving the way for improved performance of optoelectronic devices. With an improved retrieval method, the metasurface is proved to exhibit a high effective permittivity () and extremely low loss (tan δ ~ 0.005). A classical thin-film AR coating mechanism is identified through analytical derivations and numerical simulations.
多年来，由于通过表面等离激元极化激元（SPP）共振增强了入射光与器件有源层的耦合，金属孔阵列（MHA）与光电器件集成的研究兴趣不断增加。然而，由于入射介质与MHA之间的界面存在显著的反射损耗，并非所有入射光都能对SPP共振产生贡献。传统的薄膜减反射（AR）涂层通常效果不佳，因为不存在能满足AR条件且MHA有效阻抗具有强色散特性的材料。我们展示了一种单层超表面AR涂层，它能完全消除反射并显著提高SPP共振处的透射率。在非共振波长下工作时，该超表面表现出极低的损耗，且不与MHA层发生共振耦合。MHA层的SPP共振波长不受影响，而表面波显著增强，从而为光电器件性能的提升铺平了道路。通过改进的反演方法，证明该超表面具有高有效介电常数（）和极低的损耗（tan δ ~ 0.005）。通过解析推导和数值模拟确定了一种经典的薄膜AR涂层机制。
