Programmable Controls of Multiple Modes of Spoof Surface Plasmon Polaritons to Reach Reconfigurable Plasmonic Devices

Abstract

AbstractSpoof surface plasmon polaritons (SSPPs) can be supported and propagated on metal surfaces decorated with periodic subwavelength structures, whose dispersion properties are determined by geometrical dimensions of unit structures. However, the functions of plasmonic devices made of the conventional passive SSPPs will be fixed once the devices are fabricated. Here, an electronically controlled programmable SSPP waveguide is presented, whose dispersions can be manipulated in real time at fast speed by programing the bias voltage instead of changing the dimensions of the unit structures. There are three different modes at different frequency bands, with a forbidden band existing between the first‐order (fundamental) mode and the third‐order mode, where the second‐order mode cannot be propagated. By loading varactor diodes in the unit structure, the dispersions of SSPPs can be controlled by changing the capacitance of the loaded varactor diode. The proposed programmable SSPPs have a unique advantage of designing smart plasmonic devices with reconfigurable functions. As an example, a compact plasmonic waveguide with reconfigurable rejection bands is designed, simulated, and measured, showing that the central frequency, the number, and bandwidth of the rejection bands can be freely reconfigured in real time by programming the bias voltages.