Bossard Jeremy A, Yun Seokho, Werner Douglas H, Mayer Theresa S
Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Opt Express. 2009 Aug 17;17(17):14771-9. doi: 10.1364/oe.17.014771.
Negative index metamaterial designs for the mid-infrared with low absorption and impedance mismatch losses are presented. A robust genetic algorithm is employed to optimize the flexible metamaterial structure for targeted refractive index and impedance values. A new figure of merit is introduced to evaluate the impedance match of the metamaterial to free space. Two designs are presented demonstrating low-loss characteristics for a thin metamaterial with two metal screens and a thick metamaterial stack with five screens. The device performance is analyzed when adding more screens to the structure, revealing that optimizing a thick stack produces a metamaterial with properties approaching those of a bulk material.
本文提出了用于中红外波段的具有低吸收和阻抗失配损耗的负折射率超材料设计。采用了一种强大的遗传算法来优化柔性超材料结构，以实现目标折射率和阻抗值。引入了一种新的品质因数来评估超材料与自由空间的阻抗匹配。给出了两种设计，展示了具有两个金属屏的薄超材料和具有五个屏的厚超材料堆叠的低损耗特性。分析了在结构中增加更多屏时的器件性能，结果表明优化厚堆叠可产生性能接近块状材料的超材料。
