Optical anapole modes in hybrid metal–dielectric nanoantenna for near-field enhancement and optical sensing

作     者：王德宝 吕靖薇 刘伟 任艳茹 李薇 许鑫辰 刘超 朱剑豪 Debao Wang;Jingwei Lv;Wei Liu;Yanru Ren;Wei Li;Xinchen Xu;Chao Liu;Paul K Chu

作者机构：School of Physics and Electronic EngineeringNortheast Petroleum UniversityDaqing 163318China Department of PhysicsDepartment of Materials Science and Engineeringand Department of Biomedical EngineeringCity University of Hong KongHong Kong 999077China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2023年第32卷第11期

页      面：296-305页

核心收录：

学科分类：080904[工学-电磁场与微波技术] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：Project supported by the Outstanding young and middleaged research and innovation team of Northeast Petroleum University (Grant No. KYCXTD201801) the Natural Science Foundation Projects of Heilongjiang Province of China (Grant No. LH2021F007) the China Postdoctoral Science Foundation (Grant No. 2020M670881) the Study Abroad returnees merit-based Aid Foundation of Heilongjiang Province of China (Grant No. 070-719900103) the Northeastern University scientific research projects (Grant No. 2019KQ74) the City University of Hong Kong Donation Research (Grant Nos. 9220061 and DON-RMG 9229021),and the City University of Hong Kong Strategic Research (Grant No. SRG 7005505) 

主　　题：light-matter interaction metal-dielectric nanoantenna anapole mode electric field enhancement optical sensing 

摘      要：Metal–dielectric nanostructures in the optical anapole modes are essential for light–matter interactions due to the low material loss and high near-field enhancement. Herein, a hybrid metal–dielectric nanoantenna composed of six wedgeshaped gold(Au) nanoblocks as well as silica(SiO2) and silicon(Si) nanodiscs is designed and analyzed by the finite element method(FEM). The nanoantenna exhibits flexibility in excitation and manipulation of the anapole mode through the strong coupling between the metal and dielectrics, consequently improving the near-field enhancement at the gap. By systematically optimizing the structural parameters, the electric field enhancement factors at wavelengths corresponding to the anapole modes(AM1 and AM2) can be increased to 518 and 1482, respectively. Moreover, the nanoantenna delivers great performance in optical sensing such as a sensitivity of 550 nm/RIU. The results provide guidance and insights into enhancing the coupling between metals and dielectrics for applications such as surface-enhanced Raman scattering and optical sensing.