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

• https://doi.org/10.1364/JOSAB.451034

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 high-Q resonances by variation of one of the system’s parameters. At the same time, the BICs are remarkably robust in the sense that a true BIC can be recovered by further tuning any of the system’s other parameters, leading to tunability of the resonance position.