SPP filters and selectors using nanoscale metal waveguide arrays with bends

We investigate numerically filters and selectors formed in metal-insulator-metal (MIM) nanoscale metal waveguide arrays (NMWAs) with bends by using the finite difference time domain (FDTD) method, and good frequency selectivity has been observed. For the central waveguide within the array, the output surface plasmon polaritons (SPPs) frequencies mainly depend on the width and the length of the central waveguide, and the coupling effect and the reflection of SPPs from the end of each waveguide have strong influences on the frequency selections of other waveguides. Thus, by changing widths and lengths of waveguides, and the gaps between adjacent waveguides, specific frequencies can be selected with special designed structures.