Mapping Local Cascaded Metasurface Pairs to Single Nonlocal Metasurfaces

We analytically demonstrate how the properties of local cascaded metasurface pairs can be mapped to those of single nonlocal metasurfaces such that their external field scattering remains identical regardless of the particular incident field. This mapping is obtained for 2-D problems by exploiting Love's equivalence principle and fundamental linear operations. We verify the mapping with simulated data and show that the mapping preserves the losslessness, passivity, and reciprocity characteristics of the original local cascaded metasurface pair.