Fibers based on propagating bound states in the continuum

Abstract

We show that a circular periodic array of $N$ dielectric cylinders supports nearly bound states in the continuum (BICs) propagating along the cylinders. These propagating nearly BICs with extremely large $Q$ factors of order $exp(\lambda N)$ are surrounded by resonant modes weakly leaking into the radiation continuum. We present leaky zones in the vicinity of different types of BICs: symmetry protected nearly BICs with the resonant width proportional to the squared propagation constant $\Gamma \sim k_z^2$, non-symmetry protected nearly BICs with finite propagation constant $k_c$ with $\Gamma \sim (k_z-k_c{)}^2$ and non-symmetry protected nearly BICs with $\Gamma \sim k_z^4$. The latter propagating nearly BICs can serve for transmission of electromagnetic signal paving a way to novel type of optical fibers. We also demonstrate weakly leaking resonant modes which carry orbital angular momentum.

6 pages, 9 figures

References in corpus (8)

• Topological nature of bound states in the radiation continuum
• Bloch bound states in the radiation continuum in a periodic array of dielectric rods
• Light enhancement by quasi-bound states in the continuum in dielectric arrays
• Bound States in the Continuum on Periodic Structures: Perturbation Theory and Robustness
• Bound states in the continuum on periodic structures surrounded by strong resonances
• Near-bound states in the radiation continuum in circular array of dielectric rods
• Guided Modes in the Plane Array of Optical Waveguides
• Trapped modes with extremely high quality factor in the subwavelength ring resonator composed of dielectric nanorods

Cited by in corpus (3)

• Nonradiating Photonics with Resonant Dielectric Nanostructures
• Bound states in the continuum in fiber Bragg gratings
• Bound States in the Continuum and Fano Resonances in the Dirac Cone Spectrum