High-Efficiency Phase and Polarization Modulation Metasurfaces

Use of metasurfaces to control the characteristics of electromagnetic waves is an emerging trend at present. Multifunctional metasurfaces, which can modulate multiple wave parameters, greatly reduce the complexity and enrich the functionality of optical systems. Herein, a high-efficiency multifunctional metasurface for operation in the terahertz band is proposed and demonstrated. Use of a trilayer structure allows the working efficiency to reach 85% at the designed operating frequency. The phase and polarization states of the transmitted waves are modulated individually via subtle adjustment of the geometric parameters of each layer. Two terahertz-band vector beam generators are demonstrated based on the proposed metasurface. The two devices individually generate radial and azimuthal terahertz vortex beams that can carry arbitrary orbital angular momentum. The experimental results demonstrate the validity of the proposed approach. This method represents a route toward easy fabrication of high-performance phase and polarization modulation metasurfaces that can improve the information-carrying capabilities of terahertz systems and offers benefits for structured light generation, optical information security, and optical communication applications.

Automated summary

The use of metasurfaces to control electromagnetic wave characteristics is an emerging trend that reduces complexity and enhances functionality in optical systems. This study proposes and demonstrates a high-efficiency multifunctional metasurface for operation in the terahertz band. By adjusting the geometric parameters of each layer, the phase and polarization of transmitted waves can be modulated individually. Experimental results validate the effectiveness of this approach, which has the potential to improve information-carrying capabilities in terahertz systems and benefit structured light generation, optical information security, and optical communication applications.