A Matrix Pencil Method to Realize Random and Sparse Metalens

We designed random and sparse metalens for one- or two- dimensional (1D or 2D) with matrix pencil method. Compared with the traditional algorithm of random and sparse that only randomizes the meta-atoms’ position, the improved method can design both the position and phase accurately . All-dielectric random metalenses are operating at 220GHz with our proposed method. Minimum reduction of focusing efficiency can be obtained with regard to a periodically arranged metalens. Our proposed random and sparse metalenses can achieve much higher efficiency while keeping polarization-independent compared with existing methods of literature searching.