In this numerical study, an all-dielectric metasurface consisting of silicon disks with tilted split gap, which can measure the refractive index and temperature is proposed. It is demonstrated that the double resonances in the near-infrared wavelength are excited by toroidal dipole (TD) resonance in different directions. Further analysis proves that the resonance at the short wavelength corresponds to the TD resonance governed by the symmetry-protected bound state in the continuum (BIC), and it can be transformed to the TD quasi-BIC resonance with a high quality-factor (Q-factor) by breaking symmetry. The spectral responses to different incidence angles are evaluated. The high Q-factor of the TD quasi-BIC makes the designed metasurface a promising sensing candidate; the results show that the sensitivity and figure of merit for refractive index sensing are 746 nm/RIU and 18650 RIU⁻¹, respectively. For temperature sensing, the sensitivity can be as high as 54 pm/°C. This study provides a new approach for the excitation of strong TD resonance quasi-BIC, which facilitates the design of high-performance sensing applications.

在这项数值研究中，提出了一种由具有倾斜分裂间隙的硅盘组成的全电介质超曲面，可以测量折射率和温度。结果表明，近红外波长的双共振是由不同方向的环形偶极子 (TD) 共振激发的。进一步分析证明，短波长处的共振对应于连续体中受对称保护束缚态（BIC）支配的TD共振，并且可以转化为具有高品质因数（Q）的TD准BIC共振-factor) 通过破坏对称性。评估了对不同入射角的光谱响应。TD 准 BIC 的高 Q 因子使设计的超表面成为有前途的传感候选者；^-1，分别。对于温度传感，灵敏度可高达 54 pm/°C。该研究为强TD共振准BIC的激发提供了一种新方法，有助于高性能传感应用的设计。