Recently, a novel class of high-Q optical resonators based on all-dielectric subwavelength nanoparticles with high refractive index has been proposed [M. V. Rybin, et al, arXiv:1706.02099, 2017]. Here we study a complex spectrum of such nanoscale resonators by means of the resonant-state expansion, treating the problem as a nonHermitian eigenproblem. We show that the high-Q features can be described within the mechanism of external coupling of open channels via the continuum. For ceramic resonators with permittivity ε = 40, we demonstrate that the quality factor of a trapped mode with a low azimuthal index could reach the value Q = 10⁴ .

Date Published: 24 August 2017
PDF: 5 pages
Proc. SPIE 10343, Metamaterials, Metadevices, and Metasystems 2017, 103430F (24 August 2017); doi: 10.1117/12.2272375

Published in SPIE Proceedings Vol. 10343:
Metamaterials, Metadevices, and Metasystems 2017
Nader Engheta; Mikhail A. Noginov; Nikolay I. Zheludev, Editor(s)