Fig. 1: Bound state in the continuum (BIC) configuration.
From: Exceptional energy harvesting from coupled bound states
a Schematic of the fully reduced cavity (FRC) coupled to an acoustic waveguide. The z-axis is perpendicular to the xy-plane. b Numerically simulated BIC mode (M331) in terms of absolute pressure values. c 3D printed sample of the FRC. The length is set to Lx = 83.5 mm, the height to Ly = 80 mm, and the expansion in z-direction is equal to the diameter of the tube Lz = d = 40 mm to ensure a two-dimensional wave pattern. d Absorption coefficients of the numerical data (dashed orange line) and the impedance tube measurements (solid blue line). e Avoided crossing of the real parts of high-Q and low-Q modes for varying length Lx of the resonant cavity. f Vanishing imaginary part of the BIC mode.
