Enhancing sensing performance through a metal-dielectric hybrid structure supporting hybridized TPP and symmetry-protected quasi-BIC

We propose a metal-dielectric hybrid structure to enhance the quality (<i>Q</i>) factor by strong coupling between the resonant guided mode (RGM) and higher-order Tamm plasmon polariton (TPP). Meanwhile, we found that symmetry-protected bound states in the continuum (SP-BIC) can be achieved by actively adjusting the angle of the incident light, thus increasing the degrees of freedom for modulating the <i>Q</i>-factor. The simulation results indicated that both the central wavelengths and <i>Q</i>-factors of resonant modes can be modulated and optimized by modifying relevant structural parameters. Furthermore, we theoretically investigated the potential application of this structure as a dual-band self-referencing sensor, achieving the sensitivity (<i>S</i>) of up to 987.5 nm/RIU and 1237.5 nm/RIU while increasing the <i>Q</i>-factor to 923.79 and 542.73. Our work presents a promising opportunity to enhance the <i>Q</i>-factor while maintaining high <i>S</i> in lossy sensing systems.