Graphene-Integrated Tunable and Broadband Terahertz Absorber

Recently, the demand for absorbers working in terahertz frequency band is more and more diverse. In many cases, it is hoped that the absorber can achieve multiple broadband, and sometimes it is necessary to have the properties of tunability, easy processing and configuration. In this paper, we design a broadband absorber based on graphene working in terahertz range with tunability. With the increase of chemical potential energy, the wideband of high absorption changes from low frequency to high frequency. By adjusting the chemical potential of graphene, we can get two bands with high absorption which occur from 0.1 to 4.35 THz and from 7.3 to 12.7 THz with the fractional bandwidth of 191% and 54%, respectively. Meanwhile, the absorber is insensitive to polarization angle, and has great tolerance to incident angles for both Transverse Magnetic (TM) and Transverse Electric (TE) waves.