Plasmonic modulator utilizing three parallel metal-dielectric-metal waveguide directional coupler and elasto-optic effects

► Off state: Zero power appears in the output of waveguide 1 within coupling length. ► On state: Maximum power appears in the output due to mode and phase mismatching. ► Simulation results verify the theoretical concept. ► Active modulation of the surface plasmon mode in the waveguide using elasto-optics effect is novel. ► The design structure is simple for fabrication.