Xu Su, Liu Jian-Bin, Wang Hao, Su Ci-Kang, Sun Hong-Bo
Opt Lett. 2019 Feb 15;44(4):927-930. doi: 10.1364/OL.44.000927.
Metamaterials (MMs) and photonic crystals (PhCs) exhibiting artificially engineered physical properties have been widely studied in the past decade. However, abnormal properties could only be proposed under a limited range of polarization and directions in most of the previous studies. It is still a challenge to realize an isotropic artificial material with multiple exotic electromagnetic properties. Here we report a three-dimensional metacrystal supporting full polarization and omni-directional incidence. The center-symmetric unit cell consists of non-resonant closed metallic loops on each surface of the dielectric cube. With the cross-scale dispersion engineering, the metacrystal can exhibit an isotropic diamagnetic response and an all-angle negative index of refraction simultaneously at the opposite sides of the MM-PhC transition region. An additional numerical analysis shows the good performance in terahertz and mid-infrared frequencies, which indicates its potential applications on multi-functional optical components with wide polarization-and-direction allowance.
在过去十年中，具有人工设计物理特性的超材料（MMs）和光子晶体（PhCs）得到了广泛研究。然而，在大多数先前的研究中，异常特性仅在有限的偏振范围和方向下被提出。实现具有多种奇异电磁特性的各向同性人工材料仍然是一项挑战。在此，我们报道了一种支持全偏振和全向入射的三维超晶。中心对称的晶胞由介电立方体每个表面上的非谐振闭合金属环组成。通过跨尺度色散工程，该超晶在MM-PhC过渡区域的相对两侧可同时呈现各向同性抗磁响应和全角度负折射率。额外的数值分析表明其在太赫兹和中红外频率下具有良好性能，这表明其在具有宽偏振和方向容限的多功能光学元件方面具有潜在应用。
