Spectral Characteristics of Plasmonic Metal–Insulator–Metal Waveguides With a Tilted Groove

Spectral characteristics of surface plasmon polaritons (SPPs) in metal-insulator-metal (MIM) waveguides with a rectangular or V-groove are analyzed. Theoretical and simulation results indicate that both schemes can achieve wavelength filtering functionality with the center wavelength possessing a linear relationship with the length of the groove. The plasmonic MIM waveguide with a tilted groove could be regarded as the composition of a hypotenuse, rectangular, and V-shaped structures based on theoretical analyses. Characteristics of such waveguides are further investigated numerically by the finite-different time-domain (FDTD) method. The center wavelength of such structure has a nonlinear relationship with the height of the groove. The unique feature may help researchers design grooves with specified angles in nanophotonic integrated circuits.