Asymmetric tetramer metasurface sensor governed by quasi-bound states in the continuum
Zhou Yi,
Luo Man,
Zhao Xuyang,
Li Yuxiang,
Wang Qi,
Liu Zhiran,
Guo Junhong,
Guo Zhihe,
Liu Junjie,
Wu Xiang
Affiliations
Zhou Yi
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Luo Man
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Zhao Xuyang
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Li Yuxiang
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Wang Qi
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Liu Zhiran
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Guo Junhong
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Guo Zhihe
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Liu Junjie
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Wu Xiang
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai200433, P. R. China
Asymmetric metasurfaces supporting quasi-bound states in the continuum (BICs) with high Q-factors and strong light–matter interaction properties are attractive platforms for label-free biosensing applications. Recently, various meta-atom geometries have been exploited to support sharp high-Q quasi-BIC resonance. However, which meta-atom design may be a better practical choice remains unclear. Here, we compared several established meta-atom designs to address this issue by conducting an extensive theoretical discussion on sensing capability and fabrication difficulty. We theoretically revealed that the tetramer meta-atom geometry produces a higher surface sensitivity and exhibits a larger size-to-wavelength ratio than other meta-atom schemes. Furthermore, we found that metasurfaces with a higher depth considerably enhance surface sensitivity. The performance of two asymmetric tetramer metasurfaces (ATMs) with different heights was demonstrated experimentally. Both shallow and thick ATM structures exhibit sharp high Q-factor resonances with polarization-insensitive features. Notably, the surface sensitivity is 1.62 times for thick ATM compared to that for shallow ones. The combination of properties opens new opportunities for developing biosensing or chemical-sensing applications with high performance.
