High-Q refractive index sensors based on all-dielectric metasurfaces. Issue 33 (2nd August 2022)

• Record Type: Journal Article
• Authors: Wu, Pinghui; Qu, Shuangcao; Zeng, Xintao; Su, Ning; Chen, Musheng; Yu, Yanzhong
• Is Part Of: RSC advances. Volume 12:Issue 33(2022)
• Page Start: 21264
• Page End: 21269
• Publication Date: 2022-08-02
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2ra02176e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A high-sensitivity refractive index sensor excited by the 2D periodic TiO2 dielectric grating structure. The nanosensor can excite guided-mode resonance with a 0.19 nm ultra-narrow linewidth. Low loss all-dielectric metasurface allows ultra-sensitive biosensor detection. Abstract : Possessing fantastic abilities to freely manipulate electromagnetic waves on an ultrathin platform, metasurfaces have aroused intense interest in the academic circle. In this work, we present a high-sensitivity refractive index sensor excited by the guided mode of a two-dimensional periodic TiO2 dielectric grating structure. Numerical simulation results show that the optimized nanosensor can excite guided-mode resonance with an ultra-narrow linewidth of 0.19 nm. When the thickness of the biological layer is 20 nm, the sensitivity, Q factor, and FOM values of the nanosensor can reach 82.29 nm RIU −1, 3207.9, and 433.1, respectively. In addition, the device shows insensitivity to polarization and good tolerance to the angle of incident light. This demonstrates that the utilization of low-loss all-dielectric metasurfaces is an effective way to achieve ultra-sensitive biosensor detection.