Tunable Reflective Electromagnetic Wave Beam Scattering for Mid-Infrared Coded Metamaterials

A digital coded metasurface uses a digital state to represent electromagnetic parameters and directly connects digital technology at the information level with metasurface units at the physical level. Based on the dynamic properties of the phase-change material, a tunable reflective coded metasurface was constructed by integrating the phase-change material into coded units. By using the parameter scanning optimization method, the geometric phase element was optimized to construct different coded sequences. In order to flexibly regulate reflected beams, the Fourier convolution principle in digital signal processing was introduced. Using the Fourier convolution addition operation on two different sequences of the coded metasurface, a synthetic coded sequence was obtained to achieve flexible regulation of beam reflection. Based on the tunable properties of the phase-change material, the dynamic multi-angle reflection of a coded metasurface can be achieved by a different coding convolution operation.