Frequency splitter based on graphene plasmonic waveguide

A novel frequency splitter based on graphene plasmonic waveguide with composite periodic grating is proposed and demonstrated numerically. The graphene surface plasmon polarition (GSPP) modes with different eigenfrequencies are supported in the composite periodic grating waveguide due to the dispersion relation depended on the geometric structure. The light wave with single frequency can propagate in the single periodic grating. Based on the characteristics of GSPP, the frequency splitter is realized by the graphene waveguide with composite periodic grating and single periodic grating branch in the terahertz spectral region. Simulation results prove that the GSPP waves in the wavelength range from 8 µm to 10 µm can be separated into the two independent branches. The loss of the GSPP wave in the two branch has large disparity between the dissimilar frequencies.