Tunable plasmonic filter and variable optical attenuator based on ring metal–insulator–metal waveguide

Abstract

A tunable nanoscale plasmonic filter and variable optical attenuator structure based on a rectangular ring metal–insulator–metal waveguide cavity containing electro‐optic (EO) material is proposed and numerically demonstrated by using the finite‐difference time‐domain technique. The simulation results show that the output of the device can be electrically controlled by tuning the refractive index of the EO material and the structure can be used as tunable filter and variable optical attenuator alternatively under very low voltage.