High-Performance Sensitive TE/TM Mode Switch With Graphene-Based Metal-Dielectric Resonances

We explore the performance of the monolayer graphene with a metal-dielectric compound grating via numerical simulation. The results show that the absorption peaks can be near 100% at 68.36 THz for both TE and TM polarizations. Different spectral line shapes are displayed under different polarization states, we attribute the excellent absorption performance to the excitation of magnetic resonance (MR) and cavity mode resonance (CMR), and then an equivalent capacitance-inductance (LC) circuit model and the waveguide theory are used to explain it theoretically. We have also studied the influence of the polarization angle on the absorption performance, and found that as the polarization angle increases, the resonance wavelength remains unchanged but the FWHM of absorption spectrum increases gradually. Based on this feature, we apply it in mode switch which can easily switch its function as absorption or sensing by adjusting the polarization states of incident radiations.