Figure 1: PTI and POI.
From: Experimental realization of photonic topological insulator in a uniaxial metacrystal waveguide
Both insulators are waveguides filled with hexagonal metacrystals. (a) Photograph of two experimental samples with the top copper plate removed to show the geometry inside. Spin-filtered EM waves are guided at the edge (green line) between both insulators. (b) Zoom-in near the edge. The hexagonal unit cells of PTI (blue and cyan hexagons) and POI (pink and red hexagons) are composed of ‘gyro’ and ‘star’ non-resonant meta-atoms. (c,d) Geometry dimensions for POI. (e,f) Geometry dimensions for PTI.
