[7a-A410-1~10] 3.11 Photonic structures and phenomena

[7a-A410-3] Photonic Topological Insulator Based on Si Photonic Crystal Resonator Array

〇Kenta Takata^1,2, Masaya Notomi^1,2,3 (1.NTT NPC, 2.NTT BRL, 3.Tokyo Inst. Tech.)

Keywords:topological photonics, photonic crystal, coupled resonators

We propose a two-dimensional photonic topological insulator with coupled Si photonic crystal nanocavities, which can suppress vertical radiation loss. A crystal-type photonic topological insulating phase based on the C₆ rotational symmetry is realized by a triangular lattice of hexagonal units of optimized H1 cavities. With a tight-binding analysis and a simulation with the finite element method, we show theoretically its band inversion, finite Z₂ topological number, and midgap edge states between the considered topological and ordinary photonic insulators.