Plasmonic filters and optical directional couplers based on wide Metal-Insulator-Metal structure.

The wide Metal-Insulator-Metal (WMIM) structure is proposed and its characteristics are analyzed numerically using finite-difference time-domain (FDTD) method. Simulations show that power can be periodically transferred between its two Metal-Insulator (MI) interfaces while power is injected asymmetrically. Novel plasmonic filters and optical directional couplers (ODCs) based on WMIM structure are proposed, which work similarly as traditional dielectric devices.