摘要
近年来,连续体中的束缚态因具有极强的促进光与物质相互作用的能力,是实现具有超高品质因子的光学共振的理想平台,成为研究的热点.本工作设计了一个单元胞由硅圆盘构成的全介质超表面,在此超表面上观察到一个对称保护的束缚态,当面内对称性被破坏时,其可以转化为具有高质量品质因子的准束缚态.随着背景折射率的改变,共振峰的位置随之变化,通过这一原理实现了一种生物折射率传感器.由于品质因子和不对称参数成二次反比关系,通过调节不对称参数,品质因子也会发生改变,从而实现传感性能的提升和调节.经过调节,该超表面的折射率传感灵敏度和优值分别达到162.55 nm/RIU和1711.05 RIU^(-1),高于大部分的现有报道结果.本工作的高品质因子全介质超表面设计为高灵敏度和高精度的生物检测提供了新的途径.
In recent years,bound states in the continuum(BICs)have become a hot research topic because of their strong ability to facilitate light-matter interactions,and they are also an ideal platform for realizing optical resonances with ultra-high quality factors(Q).Nowadays,BICs have been found to exist in various photonic microstructures and nanostructures such as waveguides,gratings,and metasurfaces,among which metasurfaces have attracted much attention due to their ease of adjustment and considerable robustness.Traditional precious metal-based metasurfaces inevitably have low Q-factors due to the inherent defect of high ohmic losses.In contrast,due to lower ohmic losses,all-dielectric metasurfaces can be an excellent alternative to metallic metasurface structures.In this work,an all-dielectric metasurface is designed,with a silicon disc as the unit cell,and symmetric protected BIC(SP-BIC)is observed on the metasurface.When introducing eccentric holes to break the symmetry in the structural plane(QBIC),the SP-BIC can be transformed into a quasi-BIC,with radiation dominated by magnetic dipoles and has a high-quality Q-factor.For QBICs formed on the metasurface,the resonance wavelength is usually greatly dependent on the refractive index of the surroundings due to the strong localization of the electric field within the cell.As the refractive index of the background changes,the positions of the resonance peaks change accordingly,and identification sensing of some biological components is achieved by this principle.This metasurface-based bio-refractive index sensor is less invasive in free space and is expected to overcome the drawbacks of traditional electrochemical-based biosensing technologies,which have cumbersome detection steps and high time and material costs.In terms of sensing parameters,due to the quadratic inverse relationship between the quality factor and asymmetric parameters,by adjusting the asymmetric parameters,the quality factor will also change,thereby enhancing and adjusting the sensing performance.After adjusting,the refractive index sensing sensitivity and figure of merit of this metasurface reach 162.55 nm/RIU and 1711.05 RIU^(-1),respectively,which are higher than those achieved in many other existing studies.This high Q-factor all-dielectric metasurface design provides a new avenue for achieving high-sensitivity and high-precision bio-detect ion.
作者
王军辉
李德琼
聂国政
詹杰
甘龙飞
陈智全
兰林锋
WANG Junhui;LI Deqiong;NIE Guozheng;ZHAN Jie;GAN Longfei;CHEN Zhiquan;LAN Linfeng(Hunan Provincial Key Laboratory of Intelligent Sensors and New Sensor Materials,School of Physics and Electronic Science,Hunan University of Science and Technology,Xiangtan 411201,China;School of Mathematics and Statistics,Hunan University of Technology and Business,Changsha 410205,China;School of Microelectronics and Physics,Hunan University of Technology and Business,Changsha 410205,China;Luminescence Materials and Devices National Key Laboratory,South China University of Technology,Guangzhou 510640,China)
出处
《物理学报》
北大核心
2025年第10期297-305,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号:62173135)
湖南省教育厅自然科学基金(批准号:23A0454,22A0433,22A0435)
湖南省自然科学基金(批准号:2022JJ30301,2023JJ30195)资助的课题。
关键词
全介质超表面
连续体束缚态
折射率传感
光学生物传感
all-dielectric metasurface
bound states in the continuum
refractive index sensing
optical biosensing
