Large and Complete Topological Bandgaps with Edge modes in Symmetric SOI Photonic Crystal Slabs

We successfully fabricated symmetric silicon-on-insulator photonic crystal slabs that materialized wide topological bandgaps and edge modes for the lowest-order symmetric TE (transverse electric)-like modes. We confirmed their complete bandgaps by high-angle-resolution reflection measurements and polarization selection rules, and detected the presence of edge modes.