Robust valley transport of disordered topological waveguide in visible light waveband

The widely studied topological edge states are protected against weak disorder, but this topological protection breaks down for a sufficiently strong disorder. Here, a 2D valley-Hall topological photonic insulator (PTI) with strong robust structure is constructed inspired by metallic nanoparticle metamaterials, working in the visible light band. Based on the multilevel nested structure of the PTI, it is easy to construct topological waveguides with large defects in each unit cell and lead to a strong global disorder. The robust transport of edge states is verified in the global disordered topological waveguide by simulation, and there is no noticeable performance degradation. By introducing systematic disorder, the degradation process of robustness is evaluated. This study enriches the design of valley-Hall PTIs in visible light waveband and provides progress in disordered topological photonic devices.