▎ 摘　　要

In this article, two tri-mode perfect absorbers are designed by using hybrid resonance cavities with graphene monolayers. By making the subwavelength grating located inside or outside the defect of photonic crystal (PC), two hybrid Fabry-Perot (FP)-Fano cavities are formed. With the co-effect of FP resonance and Fano resonance, three perfect absorption modes for each structure appear at the critical coupling. The amplitudes or positions of these modes can be adjusted freely by tuning the chemical potential of graphene or the angle of incident wave while the relative positions and the interval between these modes can be manipulated by changing the geometry of cavities. Besides, the system shows outstanding sensing performance at the high-Q mode. Therefore, these modes are controllable and proposed structures can act not only as the absorbers but also as modulators, sensors and reflectors.