▎ 摘　　要

In order to realize the double-mode absorption, double-defect photonic crystal is formed. For the upper defect, the graphene multilayer is placed on the top of photonic crystal acting as the surface defect, while for the one below, the pure dielectric destroying the periodicity of photonic crystal services as the internal defect. Depending on FP resonance, two modes achieve perfect absorption at critical coupling. Merely, the mode-dependences are different, so that these modes have different distinctly Q factors and can be tuned independently by changing the chemical potential of graphene and the size of defect. Combining the angle response, the independence-tuning of modes becomes more flexible. Besides, both of modes' frequencies and amplitudes are enslaved to the layer number of graphene. And the period of photonic crystal affects directly the peak-peak distance and modes number.