Figure 3: Robust transport in the conceptual metacrystal waveguide.
From: Experimental realization of photonic topological insulator in a uniaxial metacrystal waveguide
Wave transport at the edge with/without defect between (a,b) PTI and the low-index waveguide, (c,d) POI and the low-index waveguide, (e,f) PTI and POI. b,f illustrate that the defect does not introduce backscattering, while d shows that the defect causes strong backscattering to the extent that there is no transmitted wave.
