Wu Pinghui, Qu Shuangcao, Zeng Xintao, Su Ning, Chen Musheng, Yu Yanzhong
Research Center for Photonic Technology, Fujian Provincial Key Laboratory for Advanced Micro-nano Photonics Technology and Devices & Key Laboratory of Information Functional Material for Fujian Higher Education, Quanzhou Normal University Quanzhou 362000 China
RSC Adv. 2022 Aug 2;12(33):21264-21269. doi: 10.1039/d2ra02176e. eCollection 2022 Jul 21.
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 TiO 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, factor, and FOM values of the nanosensor can reach 82.29 nm RIU, 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.
超表面具有在超薄平台上自由操纵电磁波的出色能力，已在学术界引起了强烈关注。在这项工作中，我们展示了一种由二维周期性TiO介电光栅结构的导模激发的高灵敏度折射率传感器。数值模拟结果表明，优化后的纳米传感器能够激发线宽仅为0.19 nm的超窄导模共振。当生物层厚度为20 nm时，该纳米传感器的灵敏度、品质因数和优值分别可达82.29 nm/RIU、3207.9和433.1。此外，该器件对偏振不敏感，对入射光角度具有良好的耐受性。这表明利用低损耗全介质超表面是实现超灵敏生物传感器检测的有效途径。
