Absence of reflectivity of the phonon-polariton at the SiC surface from the metal mask edge

Surface phonon polariton (SPhP) waves are excited at the silicon carbide ($SiC$) surface under irradiation of light close to the lattice resonance frequency. Metal mask at the surface blocks irradiation of certain areas and thus allows tuning standing or propagating wave pattern and, thus, open opportunities for surface polariton optic devices. In this study we show by means of scanning near-field microscopy that the edge of such a mask reflects SPhP waves negligibly. This condition differs dramatically from numerous recent observations of polariton reflections in 2D materials and makes the metallized $SiC$ platform advantageous in a sense of capability to calculate wavefield using a simple Green function-based approach.