Reconfigurable spoof surface-plasmon-polariton couplers

Driven by the miniaturization of integrated electronics and the increasing demand for ultrafast information transmission in communication systems, investigations into functional devices based on spoof surface plasmonic polaritons (SPPs) have garnered significant attention. However, the characteristics of spoof SPPs are related to geometric parameters of the unit structure, the functions of devices that composed by unit structures cannot be altered by changing the sizes of structures. The next focus to be investigated is the reconfigurable and active control of the device. Herein, we report a reconfigurable and direction-controllable coupler for spoof SPPs to spatial radiated waves. By changing the rotation angles of unit cells, it becomes possible to independently control the reflection phases. Through manipulation of different phase gradients, various reflection angles can be achieved at a fixed frequency. The results confirm that the proposed coupler holds great promise for applications in reconfigurable functional devices.