High-Q Quasi-bound states in the continuum metasurface for simultaneous detection of magnetic induction intensity, refractive index and temperature

Abstract

Multi-parameter sensing has become a popular research topic. However, designing multi-parameter sensors with multiple high quality-factor (Q-factor) resonances remains challenging. In order to address the challenge, we employ quasi-bound states in the continuum (quasi-BICs) to design a silicon-based metasurface multi-parameter sensor with multiple high-Q resonances. The multi-parameter sensor can support three quasi-BICs resonances with a Q-factor exceeding 10⁴, and can detect three parameters of magnetic induction intensity (B), refractive index (RI) and temperature (T) simultaneously. In order to detect the three parameters using the proposed sensor, the sensitivities for B, RI and T of the three quasi-BICs resonances are calculated, respectively. Then we exploit a three-dimensional sensitivity matrix, and obtain a matrix equation to describe the relationship between the changes of the three parameters and the resonant wavelength shifts of the three quasi-BICs resonances. By solving the matrix equation, the three parameters can be simultaneously demodulated. The proposed sensor employs quasi-BICs to obtain resonances with high Q-factors, and can simultaneously detect B, RI and T. This work provides a feasible way for designing high-Q multi-parameter sensors.