High-Sensitivity Optical Sensors Empowered by Quasi-Bound States in the Continuum in a Hybrid Metal–Dielectric Metasurface

Enhancing light–matter interaction is a key requisite in the realm of optical sensors. Bound states in the continuum (BICs), possessing high quality factors (Q factors), have shown great advantages in sensing applications. Recent theories elucidate the ability of BICs with hybrid metal–dielectric architectures to achieve high Q factors and high sensitivities. However, the experimental validation of the sensing performance in such hybrid systems remains equivocal. In this study, we propose two symmetry-protected quasi-BIC modes in a metal–dielectric metasurface. Our results demonstrate that, under the normal incidence of light, the quasi-BIC mode dominated by dielectric can achieve a high Q factor of 412 and a…

• NS
  Natural Science Foundation of Shanghai

  Awards: 22ZR1432400, 21ZR1407400
• NN
  National Natural Science Foundation of China

  Awards: 62205246, 62175035
• FR
  Fundamental Research Funds for the Central Universities