▎ 摘　　要

A tunable dual-frequency metamaterial graphene polarization converter in the infrared range is put forward in this paper. The proposed converter is made up of 3 layers-the bottom gold layer, the middle silicon dioxide layer and the upper graphene layer. The simulated results show that the polarization converter can simultaneously work at two resonant frequencies of 36.82 and 41.38 THz. The polarization conversion rates are up to 0.9992 at 36.82 THz and 0.9969 at 41.38 THz under the certain normal condition when Fermi energy is given to 1.0 eV, showing the high efficiency of the polarization converter. Moreover, the converter shows its stable working performance under the change of the incident angle and the geometrical size. Meanwhile, without varying the nanostructure, the resonant frequencies can be flexibly adjusted by controlling the Fermi energy. The superior performance of the proposed graphene polarization converter indicates a broad prospect that a large number of applications such as infrared imaging sensors, modulators, switches, photonic and biochemical sensors, light harvesting, thermal detection and electromagnetic energy converter will apply it.