Luo Hao, Luo Jie, Zhang Zhihui, Wu Chao, Li Quan, Liu Wei, Peng Ruwen, Wang Mu, Li Hongqiang, Lai Yun
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
School of Physical Science and Technology & Jiangsu key Laboratory of Frontier Material Physics and Devices, Soochow University, Suzhou, 215006, China.
Light Sci Appl. 2024 Sep 20;13(1):262. doi: 10.1038/s41377-024-01605-z.
Conventional dielectric solid materials, both natural and artificial, lack electromagnetic self-duality and thus require additional coatings to achieve impedance matching with free space. Here, we present a class of dielectric metamaterials that are effectively self-dual and vacuum-like, thereby exhibiting full-polarization omnidirectional impedance matching as an unusual Brewster effect extended across all incident angles and polarizations. With both birefringence and reflection eliminated regardless of wavefront and polarization, such anisotropic metamaterials could establish the electromagnetic equivalence with "stretched free space" in transformation optics, as substantiated through full-wave simulations and microwave experiments. Our findings open a practical pathway for realizing unprecedented polarization-independence and omnidirectional impedance-matching characteristics in pure dielectric solids.
传统的介电固体材料，无论是天然的还是人造的，都缺乏电磁自对偶性，因此需要额外的涂层来实现与自由空间的阻抗匹配。在此，我们展示了一类具有有效自对偶性且类似真空的介电超材料，从而呈现出全极化全向阻抗匹配，这是一种跨越所有入射角和极化的异常布儒斯特效应。由于无论波前和极化如何，双折射和反射都被消除，这种各向异性超材料可以在变换光学中与“拉伸自由空间”建立电磁等效性，全波模拟和微波实验证实了这一点。我们的发现为在纯介电固体中实现前所未有的极化无关性和全向阻抗匹配特性开辟了一条实用途径。
