[24p-D214-1~11] 3.16 Optics and Photonics English Session

▲ [24p-D214-5] Influence of a structural defect in a topological waveguide based on a square-lattice photonic topological insulator

〇Chengkun Zhang^1,2, Hironobu Yoshimi^1,2, Yasutomo Ota³, Satoshi Iwamoto^1,2 (1.RCAST, 2.IIS, 3.Keio Univ.)

Keywords:photonic topological insulator, waveguide, defect

Photonic topological insulators (PTIs) based on photonic crystal (PhC) structures attract particular attention since the robust waveguiding properties of helical edge states supported in the PTIs are attractive for integrated photonics. The edge states in hexagonal-lattice PTIs, which have been widely studied, inherently suffer from the radiation loss during propagation since the edge states are above the light line. To address this issue, we proposed a square-lattice PTIs that can host helical edge states below the light line and numerically demonstrated the edge states below the light line are almost free from the radiation loss. In this study, we investigate the influence of a defect on the light transport properties of the edge states.