Zhang Cheng, Hong Nina, Ji Chengang, Zhu Wenqi, Chen Xi, Agrawal Amit, Zhang Zhong, Tiwald Tom E, Schoeche Stefan, Hilfiker James N, Guo L Jay, Lezec Henri J
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
Maryland Nanocenter, University of Maryland, College Park, MD, 20742, USA.
ACS Photonics. 2018;5. doi: 10.1021/acsphotonics.8b00086.
Hyperbolic metamaterials are optical materials characterized by highly anisotropic effective permittivity tensor components having opposite signs along orthogonal directions. The techniques currently employed for characterizing the optical properties of hyperbolic metamaterials are limited in their capability for robust extraction of the complex permittivity tensor. Here we demonstrate how an ellipsometry technique based on total internal reflection can be leveraged to extract the permittivity of hyperbolic metamaterials with improved robustness and accuracy. By enhancing the interaction of light with the metamaterial stacks, improved ellipsometric sensitivity for subsequent permittivity extraction is obtained. The technique does not require any modification of the hyperbolic metamaterial sample or sophisticated ellipsometry set-up, and could therefore serve as a reliable and easy-to-adopt technique for characterization of a broad class of anisotropic metamaterials.
双曲超材料是一种光学材料，其特征在于具有高度各向异性的有效介电常数张量分量，这些分量在正交方向上具有相反的符号。目前用于表征双曲超材料光学特性的技术在稳健提取复介电常数张量的能力方面存在局限性。在此，我们展示了如何利用基于全内反射的椭圆偏振测量技术，以更高的稳健性和准确性来提取双曲超材料的介电常数。通过增强光与超材料堆叠结构的相互作用，可获得用于后续介电常数提取的更高椭圆偏振测量灵敏度。该技术不需要对双曲超材料样品进行任何修改，也不需要复杂的椭圆偏振测量装置，因此可以作为一种可靠且易于采用的技术，用于表征一大类各向异性超材料。
