Index-tuning analysis and innovative applications of bound states in the continuum in high-contrast dielectric gratings

Hsin Yu Yao^1*, Tsing Hua Her², Yi Chen Wang³, Fatemeh Hadavandmirzaee², Tsun Hsu Chang³

¹Physics, National Chung Cheng University, Chiayi, Taiwan
²Physics and Optical Science, The University of North Carolina at Charlotte, North Carolina, Uzbekistan
³Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Hsin Yu Yao, email:hsinyuyao@ccu.edu.tw

We present theoretical analyses of the sensitivity of index tuning for accidental and symmetry-protected bound states in the continuum (BIC) within high-contrast all-dielectric gratings. In the case of accidental-BIC, the tuning behavior is jointly determined by the interference of multiple waveguide-array modes (WAMs). Conversely, for symmetry-protected BIC, the tuning behavior is dictated by the high-Q Fabry-Perot resonance of a single anti-symmetry WAM. Furthermore, we will introduce several innovative applications, such as optical modulators, spatial filters, and optical limiters.

Keywords: high-contrast gratings, Fano resonance, Spatial filter, Refractive-index tuning, Optical limiter