A plasmonic electro-optical variable optical attenuator based on side-coupled metal–dielectric–metal structure

A plasmonic variable optical attenuator based on side-coupled single and double-teeth metal–dielectric–metal structure filled with an electro-optical material is proposed and numerically simulated by using the finite-difference time-domain technique with a perfectly matched layer boundary condition. The simulation results demonstrate that the output light intensity of the device can be electrically controlled by tuning the refractive index of the electro-optical material. The double-teeth structure exhibits a larger tuning range and a broader bandwidth than the single tooth one.