Author(s): Chao, MH (Chao, Minghao); Liu, QS (Liu, Qingsong); Zhang, WJ (Zhang, Wenjing); Zhuang, LY (Zhuang, Lingyun); Song, GF (Song, Guofeng)

Source: OPTICS EXPRESS Volume: 30 Issue: 16 Pages: 29258-29270 DOI: 10.1364/OE.457274 Published: AUG 1 2022

Abstract: Recently, high-order topological photonic crystals (PhCs) have attracted huge research attention due to their novel physics mechanism and the application potential in integrated photonics. Based on the two-dimensional Su-Schrieffer-Heeger model, we construct and study the mutual coupling between the high-order corner states in 2D dielectric PhCs. Simulation results show that the Q-factor of such corner-localized quasi-bound states in the continuum (BICs) could be enhanced tbllowing mutual coupling in finite size. Furthermore, we study the side-coupled structure based on defect-hybrid waveguides and the edge state microring, the quasi-BIC microcavity. The refractive index sensing application based on corner-localized quasi-BICs shows outstanding simulated sensitivity (312.8 nm/RIU) and figure of merit (similar to 10(3) 1/RIU). The robustness against fabrication errors due to its topologically protected nature makes it competitive compared with other quasi-BICs sensors. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Accession Number: WOS:000836698500081

ISSN: 1094-4087

Full Text: https://opg.optica.org/oe/fulltext.cfm?uri=oe-30-16-29258&id=481846