Fabrication robustness in BIC metasurfaces

Abstract All-dielectric metasurfaces supporting photonic bound states in the continuum (BICs) are an exciting toolkit for achieving resonances with ultranarrow linewidths. However, transition from theory to experimental realization can significantly reduce optical performance of BIC-based nanophotonic systems, severely limiting their application potential. Here, we introduce a combined numerical/experimental methodology predicting how unavoidable tolerances nanofabrication such as random geometrical variations affect different BIC metasurface designs. We compare several established all-dielectric unit cell geometries broken in-plane inversion symmetry including tilted ellipses, asymmetric double rods, and split rings. Significantly, even low fabrication-induced changes, both resonance amplitude its quality factor (Q-factor) reduced. find that ellipses maintain highest Q-factors throughout variation range, whereas rod ring fall off more quickly. The same behavior is confirmed experimentally, where values derived automated processing sets scanning electron microscopy (SEM) images. Our provides crucial insights into degradation when moving simulations fabricated samples will enable development robust, high-Q, easy manufacture platforms applications ranging biomolecular sensing higher harmonic generation.