Engineering the Complex-Valued Constitutive Parameters of Metamaterials for Perfect Absorption

• Main Authors: Pengwei Wang, Naibo Chen, Chaojun Tang, Jing Chen, Fanxin Liu, Saiqian Sheng, Bo Yan, Chenghua Sui
• Format: Article
• Language: English
• Published: SpringerOpen 2017-04-01
• Series: Nanoscale Research Letters
• Subjects: Metamaterials; Perfect absorbers; Anti-reflection coating; Light harvesting
• Online Access: http://link.springer.com/article/10.1186/s11671-017-2048-2
• ISSN: 1931-7573; 1556-276X

Abstract We theoretically studied how to directly engineer the constitutive parameters of metamaterials for perfect absorbers of electromagnetic waves. As an example, we numerically investigated the necessary refractive index n and extinction coefficient k and the relative permittivity ε and permeability μ of a metamaterial anti-reflection layer, which could cancel the reflection from a hydrogenated amorphous silicon (α-Si:H) thin film on a metal substrate, within the visible wavelength range from 300 to 800 nm. We found that the metamaterial anti-reflection layer should have a negative refractive index (n < 0) for short-wavelength visible light but have a positive refractive index (n > 0) for long-wavelength visible light. The relative permittivity ε and permeability μ could be fitted by the Lorentz model, which exhibited electric and magnetic resonances, respectively.