Cao Yinghao, Zhang Siwen, Sun Xiaodong, Wu Feng
J Opt Soc Am A Opt Image Sci Vis. 2020 Jul 1;37(7):1128-1134. doi: 10.1364/JOSAA.393882.
Comprehensive investigations of absorption enhancement by a period array of nano-grooves in gold substrate are provided. A simple Fabry-Perot model is presented to explore impact factors on absorption enhancement. The impacts of structural parameters on absorption enhancement for an array of nano-grooves are explored and discussed. Our calculations show that complete absorption (about 1) can be obtained with the groove depth fulfilling the Fabry-Perot resonance condition. The effect of groove width on absorption for a trapezoidal groove array is slightly different from that for a rectangular groove array, because of the impact of single-pass loss in the grooves. Surface plasmon resonance that can carry most of the energy away from grooves and propagate along the metal surface could lead to extremely low absorption for a period array of nano-grooves. Our discussions identify two key roles in absorption enhancement for a nano-groove array: the fundamental groove mode resonance and the generation of surface plasma polaritons. In addition, the analysis of absorption enhancement for an array of trapezoidal grooves can also provide a comprehensive contribution of Fabry-Perot resonance and electromagnetic interaction along the bevel edges of the trapezoidal grooves.
本文对金基底上纳米槽周期阵列增强吸收进行了全面研究。提出了一个简单的法布里 - 珀罗模型来探究吸收增强的影响因素。探讨并讨论了纳米槽阵列结构参数对吸收增强的影响。我们的计算表明，当槽深满足法布里 - 珀罗共振条件时，可实现完全吸收（约为1）。梯形槽阵列中槽宽对吸收的影响与矩形槽阵列略有不同，这是由于槽内单程损耗的影响。表面等离子体共振会将大部分能量带离槽并沿金属表面传播，这可能导致纳米槽周期阵列的吸收极低。我们的讨论确定了纳米槽阵列吸收增强中的两个关键作用：基本槽模共振和表面等离子体激元的产生。此外，对梯形槽阵列吸收增强的分析还可以提供法布里 - 珀罗共振和沿梯形槽斜边电磁相互作用的综合贡献。
