Toggling Near?Field Directionality via Polarization Control of Surface Waves

Directional excitation of guidance modes is central to many applications ranging from light harvesting, optical information processing quantum technology. Of paramount interest, especially, the active control near-field directionality provides a new paradigm for real-time on-chip manipulation light. Here, it found that given dipolar source, its can be toggled efficiently via tailoring polarization surface waves are excited, example, tuning chemical potential graphene in graphene-metasurface waveguide. This finding enables feasible scheme directionality. Counterintuitively, revealed this transform circular electric/magnetic dipole into Huygens coupling. Moreover, Janus dipoles, actively flipping their coupling and non-coupling faces.