Bound state in the continuum in an anisotropic photonic crystal supported by full-wave phase plate

TL;DR

This paper demonstrates the existence and tunability of bound states in the continuum (BICs) within an anisotropic photonic crystal system, showing their robustness and potential for high-Q resonances.

Contribution

It analytically shows that anisotropic defect layers in photonic crystals support accidental BICs and explores their tunability and robustness.

Findings

BICs can be supported in anisotropic multilayered systems.

BICs can be transformed into high-Q resonances through parameter variation.

True BICs are robust and can be recovered by tuning system parameters.

Abstract

We consider bound states in the continuum (BICs) in a 1D multilayered system of an anisotropic defect layer embedded into an anisotropic photonic crystal. We analytically demonstrate that an anisotropic defect layer embedded into anisotropic photonic crystal supports accidental BICs. These BICs can be transformed to a high-Q resonances by variation of one of the system's parameters. At the same time the BICs are remarkably robust in a sense that a true BIC can be recovered by further tuning any of the other system's parameters leading to tunability of the resonance position.