Electrical control of terahertz polarization by graphene microstructure

In this letter, we proposed and numerically analyzed an electric controlling polarization modulator of the terahertz wave, which is composed of a graphene monolayer microstructure with an L-shaped nanoholes array. The graphene microstructure is employed to excite the plasmonic dipolar and quadrupolar resonances in terahertz region. Through the superposition of the cross-polarized wave radiated by these plasmonic resonances, the polarization rotation effect can be obtained. Utilizing the capacitor doping, the rotation angle can be controlled by the external applied voltage, thus achieving a tunable polarization modulator.