Design and simulation of a nanoscale electro-plasmonic 1 × 2 switch based on asymmetric metal-insulator-metal stub filters.

A compact nanoscale electro-plasmonic 1 × 2 switch based on asymmetrical metal-insulator-metal stub filters is introduced. The structure is designed and analyzed based on the transmission line method, and the switching operation of the device is numerically simulated and verified by the finite element method. It is found that by adjusting the length of the stubs on each output branch of the structure the surface plasmon polaritons (SPPs) are guided to only one of the output ports. By altering the refractive index of the electro-optical material (DAST) as the core of the structure with a 35 V applied voltage, the SPPs are steered to the opposite port. The reflected SPPs from one stub filter enhance the output intensity of another filter. The operating wavelength of the switch is the communication wavelength λ=1550 nm. Nevertheless, it can be easily redesigned for another wavelength in the range of 800-2000 nm. The insertion losses and the extinction ratios guarantee an almost symmetrical switching for two outputs. The overall size of the switch is 800 nm × 450 nm × 750 nm. The bandwidth of the switch is anticipated over 100 GHz.