▎ 摘　　要

A graphene-based absorber is presented based on elliptical slots and a complementary sinusoidal-patterned dielectric layer. The proposed absorber structure includes upper dielectric and metal film layers resulting in a Fabry-Perot cavity. The produced cavity enhances the confinement of electromagnetic waves. The presented absorber yields an absolute bandwidth of 4.02 THz(0.51-4.53 THz) considering an 0.88 absorbance level together with normal incidence. The presented structure benefits from an almost insensitive ultra-wideband absorbing performance as theta varies up to 50 degrees and 60 degrees for TE and TM polarizations, respectively. Moreover, the considered symmetry in the design procedure results in an almost insensitive structure with respect to the phi incident angle. Finally, the obtained 160% fractional bandwidth is much greater compared to mentioned previous works in literature. (C) 2021 Optical Society of America