Bound States in the Continuum and Unidirectional Guided Resonances in Anisotropic Structures with Multiple Radiation Channels

(a) Geometry comprising three uniaxial layers and the angles showing the OA orientations. (b) Fundamental leaky mode in a fully anisotropy-symmetric structure showing PS and INT BICs. Color denotes the e −1 attenuation length of the mode. (c) Fundamental leaky mode with polar anisotropy symmetry broken ( θ f = 85°) shows a single BIC point. (d) Ratio of radiation channel amplitude in dB for the structure in (c).