Fabrication of polarization-insensitive, multi-resonant metamaterial absorber using wafer bonding of glass dielectric substrate

We present the design, fabrication and characterization of a terahertz multi-resonant metamaterial absorber showing polarization-insensitive characteristics. The proposed absorber uses Pyrex glass as a dielectric layer for higher absorption in a terahertz range and is wafer-level fabricated by thermo-compression bonding technique using gold films as intermediate layers. In addition, an array of comb-shaped hexagonal pattern is introduced as a multi-band LC resonator and symmetric geometry is used for polarization insensitivity. The fabricated absorber shows two absorption peaks at 0.98 THz and 1.55 THz with the absorptivity of 93% and 74%, respectively, and almost identical responses to the different polarization angles. (C) 2015 Elsevier B.V. All rights reserved.