A Simple Bandwidth Broadening Method of Terahertz Metamaterial Absorber by Partially Removing The Dielectric Layer

Abstract

In this paper, we demonstrate a simple bandwidth broadening method of terahertz (THz) metamaterial absorber (MA) by partially removing the dielectric layer of the MA. Two THz MAs with the dielectric layer fully covered and partially removed in the first and third quadrants were designed, while the top resonators of the MAs are in the same multiplexed cross form. The simulated FWHM (full width at half maximum) increases from 1.12 THz to 1.93 THz and the measured FWHM increases from 1.86 THz to 2.71 THz as the dielectric layer is partially removed in the first and third quadrants. The bandwidth broadening is caused by merging the blue-shifted resonant peaks corresponding to the resonances in the first and third quadrants with the resonant peaks corresponding to the resonances in the second and fourth quadrants. This design provides valuable guidance in designing broadband THz MAs.