Polarization splitter of surface polaritons

We investigate surface polaritons (SPs) at the interface associated with anisotropic metamaterials. The existence conditions and handednesses of s- and p-polarized SPs are discussed in detail, which reveal that anisotropy is necessary for coexistence of s- and p-polarized SPs. We explore the reflection and transmission properties of SPs across the boundary separating two interfaces and then find the scaling relations that ensure the elimination of the parasite out-of-plane scattering of SPs. The reflection and transmission coefficients, the Brewster's angle, and the critical angle of total reflection are developed. We propose a compact kind of polarization SP splitter, and its functional characters can be tuned by artificially designed constitutive parameters.