Near-bound states in the radiation continuum in circular array of dielectric rods

Abstract

We consider E polarized bound states in the radiation continuum (BICs) in circular periodical arrays of $N$ infinitely long dielectric rods. We find that each true BIC which occurs in an infinite linear array has its counterpart in the circular array as a near-BIC with extremely large quality factor. We argue analytically as well as numerically that the quality factor of the symmetry protected near-BICs diverges as $e^{\lambda N}$ where $\lambda$ is a material parameter dependent on the radius and the refraction index of the rods. By tuning of the radius of rods we also find numerically non-symmetry protected near-BICs. These near-BICs are localized with exponential accuracy outside the circular array but fill the whole inner space of the array carrying orbital angular momentum.

14 pages, 14 figures

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• Topological nature of bound states in the radiation continuum
• Bloch bound states in the radiation continuum in a periodic array of dielectric rods
• Electromagnetic bound states in the radiation continuum for periodic double arrays of subwavelength dielectric cylinders
• Light enhancement by quasi-bound states in the continuum in dielectric arrays
• Bound states in the continuum with high orbital angular momentum in a dielectric rod with periodically modulated permittivity
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Cited by in corpus (8)

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• Bound states in the continuum in photonic structures
• Permittivity-asymmetric quasi-bound states in the continuum
• Bound states in the continuum on periodic structures surrounded by strong resonances
• Fibers based on propagating bound states in the continuum
• Radial bound states in the continuum for polarization-invariant nanophotonics
• Engineering of the extremely high Q factor in two subwavelength dielectric resonators
• Luminescence Enhancement in One-Dimensional Mie-Resonant Arrays