Abstract

In this Letter, we investigate the formation of trapped modes with near-zero group velocities in a ring chain composed of dielectric nanorods. Two kinds of bound modes are successfully identified: the regular below-continuum-resonance (BCR) modes formed at the band edge and importantly the quasi-bound-states-in-the-continuum (BIC) trapped modes (similar to the BIC in the equivalent infinite linear chain). The lowest-order trapped mode possesses the highest $Q$ factor, which scales exponentially with the number of nanorods $N$ as $Q\sim \exp (0.325N)$ for the BCR and $Q\sim \exp (0.662N)$ for the quasi-BIC. Interestingly, a moderate high $Q$ factor $\sim {10}^5$ can be obtained for the quasi-BIC mode even with a very small $N=8$. This suggests that our nanorod-based ring resonator possesses a clear advantage over the linear chain for the same $N$. Our findings greatly expand the application scope of BIC-based phenomena.

© 2018 Optical Society of America

Bifurcation of bound states in the continuum in periodic structures

Nan Zhang and Ya Yan Lu
Opt. Lett. 49(6) 1461-1464 (2024)

Governance of Friedrich–Wintgen bound states in the continuum by tuning the internal coupling of meta-atoms

Peiliang Liu, Zhenyu Zhao, Yonghui Xue, Xuelian Zhang, Chunping Jiang, Rajour Tanyi Ako, Hua Qin, and Sharath Sriram
Opt. Lett. 49(5) 1301-1304 (2024)

Dependence of quality factor on surface roughness in crystalline whispering-gallery mode resonators

Guoping Lin, Rémi Henriet, Aurélien Coillet, Maxime Jacquot, Luca Furfaro, Gilles Cibiel, Laurent Larger, and Yanne K. Chembo
Opt. Lett. 43(3) 495-498 (2018)

Topologically enabled ultrahigh-Q chiroptical resonances by merging bound states in the continuum

Shun Wan, Keda Wang, Fatian Wang, Chunying Guan, Wenjia Li, Jianlong Liu, Andrey Bogdanov, Pavel A. Belov, and Jinhui Shi
Opt. Lett. 47(13) 3291-3294 (2022)

High-quality trapped modes in all-dielectric metamaterials

Vladimir R. Tuz, Vyacheslav V. Khardikov, Anton S. Kupriianov, Kateryna L. Domina, Su Xu, Hai Wang, and Hong-Bo Sun
Opt. Express 26(3) 2905-2916 (2018)