Reflective moiré metasurface: Challenges and opportunities

Dynamic beamforming is critical in applications such as radar detection, holographic imaging, and reconfigurable intelligent surfaces (RIS). This Perspective reviews a revolutionary and economical technique to achieve dynamic beamforming, utilizing the moir\'e pattern formed by twisted stacked metasurfaces. Research here faces challenges such as far-field calculations and the inverse design of specific radiation patterns, due to our limited understanding of the complex mode coupling between the moir\'e pattern and the metallic back plate. The authors outline potential solutions and project the future applications and research directions for the reflective moir\'e metasurface.