▎ 摘　　要

In this paper, we propose a tunable dual-band perfect absorber, which makes the thicker SiO2 dielectric as a spacer to separate the gold layer from the periodic cross-cross monolayer graphene array layer which locates the roof of whole absorber. The simulation results indicate that transforming the periodic p, the geometrical parameters of array and the thickness of SiO2 medium can make the structure achieve perfect absorption in dualband. Moreover, the resonance wavelength and absorption peak can be flexibly selected by Fermi level and relaxation time. In addition, the absorber is insensitive to incident angle, whether TM polarization or TE polarization. Therefore, the study provides a novel inspiration for the design of graphene-based tunable multi-band perfect THz absorber, which can be applied to photodetectors, chemical sensors and other optoelectronic devices.