Dielectric metasurface evolution from bulk to monolayer by strong coupling of quasi-BICs for second harmonic boosting

作     者：YINONG XIE QIANTING CHEN JIN YAO XUEYING LIU ZHAOGANG DONG JINFENG ZHU YINONG XIE;QIANTING CHEN;JIN YAO;XUEYING LIU;ZHAOGANG DONG;JINFENG ZHU

作者机构：Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection TechnologyXiamen UniversityXiamen 361005China Shenzhen Research Institute of Xiamen UniversityShenzhen 518057China Department of Electrical EngineeringCity University of Hong KongHong Kong 999077China Institute of Materials Research and Engineering(IMRE)Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore Department of Materials Science and EngineeringNational University of SingaporeSingapore 117575Singapore 

出 版 物：《Photonics Research》 (光子学研究（英文版）)

年 卷 期：2024年第12卷第4期

页      面：784-792页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：National Safety Academy Foundation(U1830116, U2130112) National Natural Science Foundation of China (62175205) Youth Talent Support Program of Fujian Province (Eyas Plan of Fujian Province)() Shenzhen Science and Technology Innovation Program (JCYJ20220530143015035) Agency for Science,Technology and Research (A20E5c0093, C210112019,C230917001, M21K2c0116, M22K2c0088, NRF2021-QEP2-03-P09) 

主　　题：monolayer harmonic quasi 

摘      要：2D materials are promising candidates as nonlinear optical components for on-chip devices due to their ultrathin structure. In general, their nonlinear optical responses are inherently weak due to the short interaction thickness with light. Recently, there has been great interest in using quasi-bound states in the continuum (q-BICs) of dielectric metasurfaces, which are able to achieve remarkable optical near-field enhancement for elevating the second harmonic generation (SHG) emission from 2D materials. However, most studies focus on the design of combining bulk dielectric metasurfaces with unpatterned 2D materials, which suffer considerable radiation loss and limit near-field enhancement by high-quality q-BIC resonances. Here, we investigate the dielectric metasurface evolution from bulk silicon to monolayer molybdenum disulfide (MoS2), and discover the critical role of meta-atom thickness design on enhancing near-field effects of two q-BIC modes. We further introduce the strongcoupling of the two q-BIC modes by oblique incidence manipulation, and enhance the localized optical field on monolayer MoS2dramatically. In the ultraviolet and visible regions, the MoS2SHG enhancement factor of our design is 105times higher than that of conventional bulk metasurfaces, leading to an extremely high nonlinear conversion efficiency of 5.8%. Our research will provide an important theoretical guide for the design of high-performance nonlinear devices based on 2D materials.