Stereo Meta-Atom Enabled Phase-Amplitude Gradient Metasurface for Circularly Polarized Waves

Simultaneously while independently controlling the phase and amplitude of electromagnetic (EM) waves is pivotal yet challenging for waves manipulation. Metasurface provides a possible approach to the challenge, but most of the reports so far are conducted on linearly polarized EM waves. Herein, a stereo meta-atom-enabled gradient metasurface that is capable of fully controlling both amplitude and phase for circularly polarized EM waves is proposed and demonstrated. As a proof-of-concept, it is shown that transmission gradient metasurfaces can deflect wave beams by the tailored phase of meta-atoms and transmission efficiency by the tailored amplitude of meta-atoms. This study further designs a metasurface to be implemented by stereo meta-atoms for fan-shaped beamforming where amplitude and phase gradients are required. The experiments prove that the metasurface realizes a good fan-shaped beam (azimuthal angle range is -30 degrees to 30 degrees). This study provides an avenue to fully manipulate wave beams by metasurfaces, which may trigger lots of interest in photonic metadevices.

Automated summary

A stereo meta-atom-enabled gradient metasurface is proposed and demonstrated, which can fully control both amplitude and phase for circularly polarized EM waves. Through the controlled phase and amplitude, the transmission gradient metasurface can deflect wave beams and adjust transmission efficiency. This study provides an avenue to fully manipulate wave beams by metasurfaces, which may trigger lots of interest in photonic metadevices.