Launching terahertz surface wave with desired directions

Surface wave (SW) has enabled promising applications in various fields. Seeking new approaches in SW control is highly desired in future integrated photonic devices. Controlling SW launching plays an important role in enabling those applications. Here, we develop a versatile platform that allows for manipulating the SW launching by engineering its phase profiles with phase discontinuities using orientation-controlled metallic apertures. Polarization-controllable anomalous SW is experimentally launched and observed in the terahertz frequencies. The proposed approach represents a significant step forward in developing SW-based plasmonic devices.